Why do fleas jump so high compared with their size?

Fleas are famous for their jumping ability because their leg muscles and elastic proteins allow them to store energy before takeoff. When released, this energy powers a rapid leap that can send a flea many times its own length into the air. This is useful for moving between hosts and escaping danger in dense fur, feathers or bedding. The ability has been studied with high-speed cameras and biomechanics, showing how small animals can exploit spring-like mechanics. Fleas are also medically important because some species can transmit pathogens and parasites.