advertent agile agog alert alive all ears all eyes assiduous at it at work attentive awake aware bright busy careful concentrated conscious diligent earnest employed engaged finical finicking finicky full of business hard at it hard at work heedful in harness intense intent intentive keen meticulous mindful nice niggling nimble observant observing occupied on duty on the on the alert on the ball on the go on the hop on the jump on the move on the run open-eared open-eyed openmouthed prompt qui vive quick ready regardful sharp sleepless smart tied up unblinking unnodding unsleeping unwinking wakeful watchful wide-awake working