Cuckoo clocks have two kinds of movements: the one-day (or 30-hour) and the eight-day movements. Some even play music and musical movements after the clock strikes the hours and half-hours. The cuckoos sound is created by two tiny pipes in the clock with bellows attached to their tops.

The clock’s movement sets off the bellows to send a puff of air into each pipe one by one when the clock strikes. Most cuckoo clocks now have automaton of the bird that appears through a small trap door while the clock is striking. The bird moves when the clock strikes by means of an arm that lifts the back of the clock carving.