Talitrus saltator, a species of sand hopper, is a common amphipod crustacean of sandy coasts around Europe. The animal's typical "hopping" movement gives the animal its common name, and is produced by a flexion of the abdomen. In order to do this, it must stand on its legs (amphipods usually rest on their sides) and suddenly extend its abdomen out from under its body. It can thus leap several inches into the air, although without any control over its direction. A great deal of scientific research has been carried out on the animal, to determine the environmental cues which it uses to control its behaviour.