The bamboo clacker was invented by Japanese farmers. It was used as a means of discouraging deer and other animals from foraging in rice and other agricultural fields. The clack of the bamboo tube, the tilting motion and the sudden rush of water was an effective deterrent. In Japanese gardens, it does have the same animal chasing qualities but is also esthetically pleasing.
(ref 3)
Bamboo clackers are made with a hollowed out length of bamboo that is mounted on a vertical base. The bamboo rod is attached so that it pivots. One side of the rod is capped so that the bamboo will hold water. The other is open and cut at an angle. When the bamboo rod is full, the weight of the water causes it to pivot. The water gushes out of the angled end. At the same time the pointed part of the angled end bumps against precisely set stones, creating a hollow sound from the now empty tube. This sudden movement and distinctive sound scares animals. The capped end is heavier, so the rod pivots back to the original position to be filled up again.
A pond pump is used to pipe water up into another vertical, hollowed out piece of bamboo. A smaller piece of bamboo makes the spigot that pours the water into the bamboo rod. After the water is dumped back into the pond or ceramic bowl, depending on the set-up, the water is recirculated through the pump. If the bamboo clacker is of the ceramic bowl variety, the pump is placed in the bottom of the bowl and hidden by cleverly placed stones.