The Dyaks do not worship idols, but they believe in certain gods and spirits, who are supposed to rule over different departments of life, and to these deities they make offerings and sing incantations at certain times.

The following are the more important gods among the Dyaks.

Singalang Burong takes the highest position in honour and dignity, and is the ruler of the spirit-world. It is doubtful what the word Singalang means, but Burong means "bird," and probably Singalang Burong means "Bird Chief." The Dyaks are great observers of omens (see Chapter XII.), and among their omens the cries of certain birds are most important.

Singalang Burong is also the god of war, and the guardian spirit of brave men. He delights in fighting, and head-taking is his glory. When Dyaks have obtained a human head, they make a great feast to the honour of this god and invoke his presence. He is the only god ever represented by the Dyaks in a material form—a carved, highly-coloured bird of grotesque shape. This figure at the Head Feast is erected on the top of a pole, thirty feet or more in height, with its beak pointing in the direction of the enemy's country, so that he may "peck at the eyes of the enemy."

Next in importance to Singalang Burong is Pulang Gana, who is the god of the earth. He is an important power according to Dyak ideas, and to him offerings are made and incantations sung at all feasts connected with Farming. They are entirely dependent upon his goodwill for a good harvest.

Salampandai is the maker of men. He hammers them into shape out of clay, and forms the bodies of children to be born into the world. There is an insect which makes at night the curious noise—kink-a-clink, kink-a-clink. When the Dyaks hear this, they say it is Salampandai at his work. When each child is formed, it is brought to the gods who ask, "What would you like to handle or use?" If it answer, "A sword," the gods pronounce it a male; but if it answer, "Cotton and the spinning-wheel," it is pronounced a female. Thus they are born as boys or girls according to their own wishes.

The Dyak believes in the existence of spirits, and he thinks that innumerable spirits inhabit the forests, the rivers, the earth, and the air. Any unusual noise or motion in the jungle, anything which suggests to the mind some invisible operation, is at once attributed by the Dyak to the presence of some spirit, unseen by human eyes, but full of mighty power. Though generally invisible, these spirits sometimes show themselves. The form they assume then is not anything very supernatural, but either a commonplace human form or else some animal—a bird, or a monkey—such as is often seen in the forests. There is, however, the chief of evil spirits, Girgasi by name, who, when seen, takes the form of a giant about three times the size of a man, is covered with rough, shaggy hair, and has eyes as big as saucers, and huge glittering teeth.There are innumerable stories told by Dyaks of their meeting with spirits in the jungle, and sometimes speaking to them. Such stories generally relate how the man who sees the spirit rushes to catch him by the leg—he cannot reach higher—in order to get some charm from him, but he is generally foiled in his attempt, as the spirit suddenly vanishes. But some men, it is believed, do obtain gifts from the spirits. If a Dyak gets a good harvest, it is attributed to some magic charm he has received from some kindly spirit. Also, if he be successful on the war-path, he is credited with the succour of some mysterious being from the spirit-world.

The spirits, according to the Dyaks, rove about the jungle and hunt for wild beasts, as the Dyaks do themselves. Girgasi, already mentioned, is specially addicted to the chase, and the Dyaks say he is often to be met hunting in the forest. There are certain animals who roam about in packs in the jungle. These are supposed to be the dogs which accompany the spirits when they are out hunting, and they attack those whom the spirits wish to kill. I have never seen one of these animals, but to judge from the description of them, they seem to be a kind of small jackal. They will follow and bark at men, and from their supposed connection with the spirits, are greatly feared by the Dyaks, who generally run away from them as fast as they can.

The spirits are said to build their invisible habitations in trees, and many trees are considered sacred, as being the abode of one or more spirits, and to cut one of these trees down would be to provoke the spirits' anger. The tops of hills are supposed to be the favourite haunts of spirits. When Dyaks fell the jungle of the larger hills, they always leave a clump of trees at the summit as a refuge for the spirits. To leave them quite homeless would be to court certain disaster from them.

From what has been said it will be seen that the spirits are much the same as their gods, and have power either to bestow favours, or cause sickness and death. They rule the conduct of the Dyak, and therefore receive the same religious homage as their gods do.

The Dyak worships his gods. He has good spirits to help him, and evil spirits to harm him. He makes sacrifices to the gods and spirits, and invokes their help in long incantations. He has omens and divination and dreams to encourage or warn him. He believes he has a soul which will live in another world, a future life differing little from his existence in the flesh.