A curious bit of wild life came to me at dusk one day in the wilderness. It was midwinter, and the snow lay deep. I was sitting alone on a fallen tree, waiting for the moon to rise so that I could follow the faint snowshoe track across a barren, three miles, then through a mile of forest to another trail that led to camp. I had followed a caribou too far that day, and this was the result—feeling along my own track by moonlight, with the thermometer sinking rapidly to the twenty-below-zero point.

There is scarcely any twilight in the woods; in ten minutes it would be quite dark; and I was wishing that I had blankets and an axe, so that I could camp where I was, when a big gray shadow came stealing towards me through the trees. It was a Canada lynx. My fingers gripped the rifle hard, and the right mitten seemed to slip off of itself as I caught the glare of his fierce yellow eyes.

But the eyes were not looking at me at all. Indeed, he had not noticed me. He was stealing along, crouched low in the snow, his ears back, his stub tail twitching nervously, his whole attention fixed tensely on something beyond me out on the barren. I wanted his beautiful skin; but I wanted more to find out what he was after; so I kept still and watched.

At the edge of the barren he crouched under a dwarf spruce, settled himself deeper in the snow by a wriggle or two till his feet were well under him and his balance perfect, and the red fire blazed in his eyes and his big muscles quivered. Then he hurled himself forward—one, two, a dozen mighty bounds through flying snow, and he landed with a screech on the dome of a beaver house. There he jumped about, shaking an imaginary beaver like a fury, and gave another screech that made one's spine tingle. That over, he stood very still, looking off over the beaver roofs that dotted the shore of a little pond there. The blaze died out of his eyes; a different look crept into them. He put his nose down to a tiny hole in the mound, the beavers' ventilator, and took a long sniff, while his whole body seemed to distend with the warm rich odor that poured up into his hungry nostrils. Then he rolled his head sadly, and went away.

Now all that was pure acting. A lynx likes beaver meat better than anything else; and this fellow had caught some of the colony, no doubt, in the well-fed autumn days, as they worked on their dam and houses. Sharp hunger made him remember them as he came through the wood on his nightly hunt after hares. He knew well that the beavers were safe; that months of intense cold had made their two-foot mud walls like granite. But he came, nevertheless, just to pretend he had caught one, and to remember how good his last full meal smelled when he ate it in October.

It was all so boylike, so unexpected there in the heart of the wilderness, that I quite forgot that I wanted the lynx's skin. I was hungry too, and went out for a sniff at the ventilator; and it smelled good. I remembered the time once when I had eaten beaver, and was glad to get it. I walked about among the houses. On every dome there were lynx tracks, old and new, and the prints of a blunt nose in the snow. Evidently he came often to dine on the smell of good dinners. I looked the way he had gone, and began to be sorry for him. But there were the beavers, safe and warm and fearless within two feet of me, listening undoubtedly to the strange steps without. And that was good; for they are the most interesting creatures in all the wilderness.

Most of us know the beaver chiefly in a simile. "Working like a beaver," or "busy as a beaver," is one of those proverbial expressions that people accept without comment or curiosity. It is about one-third true, which is a generous proportion of truth for a proverb. In winter, for five long months at least, he does nothing but sleep and eat and keep warm. "Lazy as a beaver" is then a good figure. And summer time—ah! that's just one long holiday, and the beavers are jolly as grigs, with never a thought of work from morning till night. When the snow is gone, and the streams are clear, and the twitter of bird songs meets the beaver's ear as he rises from the dark passage under water that leads to his house, then he forgets all settled habits and joins in the general heyday of nature. The well built house that sheltered him from storm and cold, and defied even the wolverine to dig its owner out, is deserted for any otter's den or chance hole in the bank where he may sleep away the sunlight in peace. The great dam, upon which he toiled so many nights, is left to the mercy of the freshet or the canoeman's axe; and no plash of falling water through a break—that sound which in autumn or winter brings the beaver like a flash—will trouble his wise little head for a moment.

All the long summer he belongs to the tribe of Ishmael, wandering through lakes and streams wherever fancy leads him. It is as if he were bound to see the world after being cooped up in his narrow quarters all winter. Even the strong family ties, one of the most characteristic and interesting things in beaver life, are for the time loosened. Every family group when it breaks up housekeeping in the spring represents five generations. First, there are the two old beavers, heads of the family and absolute rulers, who first engineered the big dam and houses, and have directed repairs for nobody knows how long. Next in importance are the baby beavers, no bigger than musquashes, with fur like silk velvet, and eyes always wide open at the wonders of the first season out; then the one-and two-year-olds, frisky as boys let loose from school, always in mischief and having to be looked after, and occasionally nipped; then the three-year-olds, who presently leave the group and go their separate happy ways in search of mates. So the long days go by in a kind of careless summer excursion; and when one sometimes finds their camping ground in his own summer roving through the wilderness, he looks upon it with curious sympathy. Fellow campers are they, pitching their tents by sunny lakes and alder-fringed, trout-haunted brooks, always close to Nature's heart, and loving the wild, free life much as he does himself.

But when the days grow short and chill, and the twitter of warblers gives place to the honk of passing geese, and wild ducks gather in the lakes, then the heart of the beaver goes back to his home; and presently he follows his heart. September finds them gathered about the old dam again, the older heads filled with plans of repair and new houses and winter food and many other things. The grown-up males have brought their mates back to the old home; the females have found their places in other family groups. It is then that the beaver begins to be busy.

His first concern is for a stout dam across the stream that will give him a good-sized pond and plenty of deep water. To understand this, one must remember that the beaver intends to shut himself in a kind of prison all winter. He knows well that he is not safe on land a moment after the snow falls; that some prowling lucivee or wolverine would find his tracks and follow him, and that his escape to water would be cut off by thick ice. So he plans a big claw-proof house with no entrance save a tunnel in the middle, which leads through the bank to the bottom of his artificial pond. Once this is frozen over, he cannot get out till the spring sun sets him free. But he likes a big pond, that he may exercise a bit under water when he comes down for his dinner; and a deep pond, that he may feel sure the hardest winter will never freeze down to his doorway and shut him in. Still more important, the beaver's food is stored on the bottom; and it would never do to trust it to shallow water, else some severe winter it would get frozen into the ice, and the beavers starve in their prison. Ten to fifteen feet usually satisfies their instinct for safety; but to get that depth of water, especially on shallow streams, requires a huge dam and an enormous amount of work, to say nothing of planning.

Beaver dams are solid structures always, built up of logs, brush, stones, and driftwood, well knit together by alder poles. One summer, in canoeing a wild, unknown stream, I met fourteen dams within a space of five miles. Through two of these my Indian and I broke a passage with our axes; the others were so solid that it was easier to unload our canoe and make a portage than to break through. Dams are found close together like that when a beaver colony has occupied a stream for years unmolested. The food-wood above the first dam being cut off, they move down stream; for the beaver always cuts on the banks above his dam, and lets the current work for him in transportation. Sometimes, when the banks are such that a pond cannot be made, three or four dams will be built close together, the back-water of one reaching up to the one above, like a series of locks on a canal. This is to keep the colony together, and yet give room for play and storage.

There is the greatest difference of opinion as to the intelligence displayed by the beavers in choosing a site for their dam, one observer claiming skill, ingenuity, even reason for the beavers; another claiming a mere instinctive haphazard piling together of materials anywhere in the stream. I have seen perhaps a hundred different dams in the wilderness, nearly all of which were well placed. Occasionally I have found one that looked like a stupid piece of work—two or three hundred feet of alder brush and gravel across the widest part of a stream, when, by building just above or below, a dam one-fourth the length might have given them better water. This must be said, however, for the builders, that perhaps they found a better soil for digging their tunnels, or a more convenient spot for their houses near their own dam; or that they knew what they wanted better than their critic did. I think undoubtedly the young beavers often make mistakes, but I think also, from studying a good many dams, that they profit by disaster, and build better; and that on the whole their mistakes are not proportionally greater than those of human builders.

Sometimes a dam proves a very white elephant on their hands. The site is not well chosen, or the stream difficult, and the restrained water pours round the ends of their dam, cutting them away. They build the dam longer at once; but again the water pours round on its work of destruction. So they keep on building, an interminable structure, till the frosts come, and they must cut their wood and tumble their houses together in a desperate hurry to be ready when the ice closes over them.

But on alder streams, where the current is sluggish and the soil soft, one sometimes finds a wonderfully ingenious device for remedying the above difficulty. When the dam is built, and the water deep enough for safety, the beavers dig a canal around one end of the dam to carry off the surplus water. I know of nothing in all the woods and fields that brings one closer in thought and sympathy to the little wild folk than to come across one of these canals, the water pouring safely through it past the beaver's handiwork, the dam stretching straight and solid across the stream, and the domed houses rising beyond.

Once I found where the beavers had utilized man's work. A huge log dam had been built on a wilderness stream to secure a head of water for driving logs from the lumber woods. When the pines and fourteen-inch spruce were all gone, the works were abandoned, and the dam left—with the gates open, of course. A pair of young beavers, prospecting for a winter home, found the place and were suited exactly. They rolled a sunken log across the gates for a foundation, filled them up with alder bushes and stones, and the work was done. When I found the place they had a pond a mile wide to play in. Their house was in a beautiful spot, under a big hemlock; and their doorway slanted off into twenty feet of water. That site was certainly well chosen.

Another dam that I found one winter when caribou-hunting was wonderfully well placed. No engineer could have chosen better. It was made by the same colony the lynx was after, and just below where he went through his pantomime for my benefit; his tracks were there too. The barrens of which I spoke are treeless plains in the northern forest, the beds of ancient shallow lakes. The beavers found one with a stream running through it; followed the stream down to the foot of the barren, where two wooded points came out from either side and almost met. Here was formerly the outlet; and here the beavers built their dam, and so made the old lake over again. It must be a wonderfully fine place in summer—two or three thousand acres of playground, full of cranberries and luscious roots. In winter it is too shallow to be of much use, save for a few acres about the beavers' doorways.

There are three ways of dam-building in general use among the beavers. The first is for use on sluggish, alder-fringed streams, where they can build up from the bottom. Two or three sunken logs form the foundation, which is from three to five feet broad. Sticks, driftwood, and stout poles, which the beavers cut on the banks, are piled on this and weighted with stones and mud. The stones are rolled in from the bank or moved considerable distances under water. The mud is carried in the beaver's paws, which he holds up against his chin so as to carry a big handful without spilling. Beavers love such streams, with their alder shade and sweet grasses and fringe of wild meadow, better than all other places. And, by the way, most of the natural meadows and half the ponds of New England were made by beavers. If you go to the foot of any little meadow in the woods and dig at the lower end, where the stream goes out, you will find, sometimes ten feet under the surface, the remains of the first dam that formed the meadow when the water flowed back and killed the trees.

The second kind of dam is for swift streams. Stout, ten-foot brush is the chief material. The brush is floated down to the spot selected; the tops are weighted down with stones, and the butts left free, pointing down stream. Such dams must be built out from the sides, of course. They are generally arched, the convex side being up stream so as to make a stronger structure. When the arch closes in the middle, the lower side of the dam is banked heavily with earth and stones. That is shrewd policy on the beaver's part; for once the arch is closed by brush, the current can no longer sweep away the earth and stones used for the embankment.

The third kind is the strongest and easiest to build. It is for places where big trees lean out over the stream. Three or four beavers gather about a tree and begin to cut, sitting up on their broad tails. One stands above them on the bank, apparently directing the work. In a short time the tree is nearly cut through from the under side. Then the beaver above begins to cut down carefully. With the first warning crack he jumps aside, and the tree falls straight across where it is wanted. All the beavers then disappear and begin cutting the branches that rest on the bottom. Slowly the tree settles till its trunk is at the right height to make the top of the dam. The upper branches are then trimmed close to the trunk, and are woven with alders among the long stubs sticking down from the trunk into the river bed. Stones, mud, and brush are used liberally to fill the chinks, and in a remarkably short time the dam is complete.

When you meet such a dam on the stream you are canoeing don't attempt to break through. You will find it shorter by several hours to unload and make a carry.

All the beaver's cutting is done by chisel-edged front teeth. There are two of these in each jaw, extending a good inch and a half outside the gums, and meeting at a sharp bevel. The inner sides of the teeth are softer and wear away faster than the outer, so that the bevel remains the same; and the action of the upper and lower teeth over each other keeps them always sharp. They grow so rapidly that a beaver must be constantly wood cutting to keep them worn down to comfortable size.

Often on wild streams you find a stick floating down to meet you showing a fresh cut. You grab it, of course, and say: "Somebody is camped above here. That stick has just been cut with a sharp knife." But look closer; see that faint ridge the whole length of the cut, as if the knife had a tiny gap in its edge. That is where the beaver's two upper teeth meet, and the edge is not quite perfect. He cut that stick, thicker than a man's thumb, at a single bite. To cut an alder having the diameter of a teacup is the work of a minute for the same tools; and a towering birch tree falls in a remarkably short time when attacked by three or four beavers. Around the stump of such a tree you find a pile of two-inch chips, thick, white, clean cut, and arched to the curve of the beaver's teeth. Judge the workman by his chips, and this is a good workman.

When the dam is built the beaver cuts his winter food-wood. A colony of the creatures will often fell a whole grove of young birch or poplar on the bank above the dam. The branches with the best bark are then cut into short lengths, which are rolled down the bank and floated to the pool at the dam.

Considerable discussion has taken place as to how the beaver sinks his wood—for of course he must sink it, else it would freeze into the ice and be useless. One theory is that the beavers suck the air from each stick. Two witnesses declare to me they have seen them doing it; and in a natural history book of my childhood there is a picture of a beaver with the end of a three-foot stick in his mouth, sucking the air out. Just as if the beavers didn't know better, even if the absurd thing were possible! The simplest way is to cut the wood early and leave it in the water a while, when it sinks of itself; for green birch and poplar are almost as heavy as water. They soon get waterlogged and go to the bottom. It is almost impossible for lumbermen to drive spool wood (birch) for this reason. If the nights grow suddenly cold before the wood sinks, the beavers take it down to the bottom and press it slightly into the mud; or else they push sticks under those that float against the dam, and more under these; and so on till the stream is full to the bottom, the weight of those above keeping the others down. Much of the wood is lost in this way by being frozen into the ice; but the beaver knows that, and cuts plenty.

When a beaver is hungry in winter he comes down under the ice, selects a stick, carries it up into his house, and eats the bark. Then he carries the peeled stick back under the ice and puts it aside out of the way.

Once, in winter, it occurred to me that soaking spoiled the flavor of bark, and that the beavers might like a fresh bite. So I cut a hole in the ice on the pool above their dam. Of course the chopping scared the beavers; it was vain to experiment that day. I spread a blanket and some thick boughs over the hole to keep it from freezing over too thickly, and went away.

Next day I pushed the end of a freshly cut birch pole down among the beavers' store, lay down with my face to the hole after carefully cutting out the thin ice, drew a big blanket round my head and the projecting end of the pole to shut out the light, and watched. For a while it was all dark as a pocket; then I began to see things dimly. Presently a darker shadow shot along the bottom and grabbed the pole. It was a beaver, with a twenty dollar coat on. He tugged; I held on tight—which surprised him so that he went back into his house to catch breath.

But the taste of fresh bark was in his mouth, and soon he was back with another beaver. Both took hold this time and pulled together. No use! They began to swim round, examining the queer pole on every side. "What kind of a stick are you, anyway?" one was thinking. "You didn't grow here, because I would have found you long ago." "And you're not frozen into the ice," said the other, "because you wriggle." Then they both took hold again, and I began to haul up carefully. I wanted to see them nearer. That surprised them immensely; but I think they would have held on only for an accident. The blanket slipped away; a stream of light shot in; there were two great whirls in the water; and that was the end of the experiment. They did not come back, though I waited till I was almost frozen. But I cut some fresh birch and pushed it under the ice to pay for my share in the entertainment.

The beaver's house is generally the last thing attended to. He likes to build this when the nights grow cold enough to freeze his mortar soon after it is laid. Two or three tunnels are dug from the bottom of the beaver pond up through the bank, coming to the surface together at the point where the center of the house is to be. Around this he lays solid foundations of log and stone in a circle from six to fifteen feet in diameter, according to the number of beavers to occupy the house. On these foundations he rears a thick mass of sticks and grass, which are held together by plenty of mud. The top is roofed by stout sticks arranged as in an Indian wigwam, and the whole domed over with grass, stones, sticks, and mud. Once this is solidly frozen, the beaver sleeps in peace; his house is burglar proof.

If on a lake shore, where the rise of water is never great, the beaver's house is four or five feet high. On streams subject to freshets they may be two or three times that height. As in the case of the musquash (or muskrat), a strange instinct guides the beaver as to the height of his dwelling. He builds high or low, according to his expectations of high or low water; and he is rarely drowned out of his dry nest.

Sometimes two or three families unite to build a single large house, but always in such cases each family has its separate apartment. When a house is dug open it is evident from the different impressions that each member of the family has his own bed, which he always occupies. Beavers are exemplary in their neatness; the house after five months' use is as neat as when first made.

All their building is primarily a matter of instinct, for a tame beaver builds miniature dams and houses on the floor of his cage. Still it is not an uncontrollable instinct like that of most birds; nor blind, like that of rats and squirrels at times. I have found beaver houses on lake shores where no dam was built, simply because the water was deep enough, and none was needed. In vacation time the young beavers build for fun, just as boys build a dam wherever they can find running water. I am persuaded also (and this may explain some of the dams that seem stupidly placed) that at times the old beavers set the young to work in summer, in order that they may know how to build when it becomes necessary. This is a hard theory to prove, for the beavers work by night, preferably on dark, rainy nights, when they are safest on land to gather materials. But while building is instinctive, skilful building is the result of practice and experience. And some of the beaver dams show wonderful skill.

There is one beaver that never builds, that never troubles himself about house, or dam, or winter's store. I am not sure whether we ought to call him the genius or the lazy man of the family. The bank beaver is a solitary old bachelor living in a den, like a mink, in the bank of a stream. He does not build a house, because a den under a cedar's roots is as safe and warm. He never builds a dam, because there are deep places in the river where the current is too swift to freeze. He finds tender twigs much juicier, even in winter, than stale bark stored under water. As for his telltale tracks in the snow, his wits must guard him against enemies; and there is the open stretch of river to flee to.

There are two theories among Indians and trappers to account for the bank beaver's eccentricities. The first is that he has failed to find a mate and leaves the colony, or is driven out, to lead a lonely bachelor life. His conduct during the mating season certainly favors this theory, for never was anybody more diligent in his search for a wife than he. Up and down the streams and alder brooks of a whole wild countryside he wanders without rest, stopping here and there on a grassy point to gather a little handful of mud, like a child's mud pie, all patted smooth, in the midst of which is a little strong smelling musk. When you find that sign, in a circle of carefully trimmed grass under the alders, you know that there is a young beaver on that stream looking for a wife. And when the young beaver finds his pie opened and closed again, he knows that there is a mate there somewhere waiting for him. But the poor bank beaver never finds his mate, and the next winter must go back to his solitary den. He is much more easily caught than other beavers, and the trappers say it is because he is lonely and tired of life.

The second theory is that generally held by Indians. They say the bank beaver is lazy and refuses to work with the others; so they drive him out. When beavers are busy they are very busy, and tolerate no loafing. Perhaps he even tries to persuade them that all their work is unnecessary, and so shares the fate of reformers in general.

While examining the den of a bank beaver last summer another theory suggested itself. Is not this one of the rare animals in which all the instincts of his kind are lacking? He does not build because he has no impulse to build; he does not know how. So he represents what the beaver was, thousands of years ago, before he learned how to construct his dam and house, reappearing now by some strange freak of heredity, and finding himself wofully out of place and time. The other beavers drive him away because all gregarious animals and birds have a strong fear and dislike of any irregularity in their kind. Even when the peculiarity is slight—a wound, or a deformity—they drive the poor victim from their midst remorselessly. It is a cruel instinct, but part of one of the oldest in creation, the instinct which preserves the species. This explains why the bank beaver never finds a mate; none of the beavers will have anything to do with him.

This occasional lack of instinct is not peculiar to the beavers. Now and then a bird is hatched here in the North that has no impulse to migrate. He cries after his departing comrades, but never follows. So he remains and is lost in the storms of winter.

There are few creatures in the wilderness more difficult to observe than the beavers, both on account of their extreme shyness and because they work only by night. The best way to get a glimpse of them at work is to make a break in their dam and pull the top from one of their houses some autumn afternoon, at the time of full moon. Just before twilight you must steal back and hide some distance from the dam. Even then the chances are against you, for the beavers are suspicious, keen of ear and nose, and generally refuse to show themselves till after the moon sets or you have gone away. You may have to break their dam half a dozen times, and freeze as often, before you see it repaired.

It is a most interesting sight when it comes at last, and well repays the watching. The water is pouring through a five-foot break in the dam; the roof of a house is in ruins. You have rubbed yourself all over with fir boughs, to destroy some of the scent in your clothes, and hidden yourself in the top of a fallen tree. The twilight goes; the moon wheels over the eastern spruces, flooding the river with silver light. Still no sign of life. You are beginning to think of another disappointment; to think your toes cannot stand the cold another minute without stamping, which would spoil everything, when a ripple shoots swiftly across the pool, and a big beaver comes out on the bank. He sits up a moment, looking, listening; then goes to the broken house and sits up again, looking it all over, estimating damages, making plans. There is a commotion in the water; three others join him—you are warm now.

Meanwhile three or four more are swimming about the dam, surveying the damage there. One dives to the bottom, but comes up in a moment to report all safe below. Another is tugging at a thick pole just below you. Slowly he tows it out in front, balances a moment and lets it go—good!—squarely across the break. Two others are cutting alders above; and here come the bushes floating down. Over at the damaged house two beavers are up on the walls, raising the rafters into place; a third appears to be laying on the outer covering and plastering it with mud. Now and then one sits up straight like a rabbit, listens, stretches his back to get the kinks out, then drops to his work again.

It is brighter now; moon and stars are glimmering in the pool. At the dam the sound of falling water grows faint as the break is rapidly closed. The houses loom larger. Over the dome of the one broken, the dark outline of a beaver passes triumphantly. Quick work that. You grow more interested; you stretch your neck to see—splash! A beaver gliding past has seen you. As he dives he gives the water a sharp blow with his broad tail, the danger signal of the beavers, and a startling one in the dead stillness. There is a sound as of a stick being plunged end first into the water; a few eddies go running about the pool, breaking up the moon's reflection; then silence again, and the lap of ripples on the shore.

You can go home now; you will see nothing more to-night. There's a beaver over under the other bank, in the shadow where you cannot see him, just his eyes and ears above water, watching you. He will not stir; nor will another beaver come out till you go away. As you find your canoe and paddle back to camp, a ripple made by a beaver's nose follows silently in the shadow of the alders. At the bend of the river where you disappear, the ripple halts a while, like a projecting stub in the current, then turns and goes swiftly back. There is another splash; the builders come out again; a dozen ripples are scattering star reflections all over the pool; while the little wood folk pause a moment to look at the new works curiously, then go their ways, shy, silent, industrious, through the wilderness night.