Reducing numbers of eastern mosquitofish without harming other wildlife is a difficult prospect, but Giovanni Polverino at the University of Western Australia and his colleagues have come up with a potential solution. They designed a robotic version of the largemouth bass (Micropterus salmoides), which naturally preys on mosquitofish.

The robot fish looks like the real predator and even mimics its swimming behaviour. It is controlled from underneath an aquarium via magnets.

Polverino’s team ran experiments in aquariums with six wild-caught eastern mosquitofish and six wild-caught tadpoles. When an overhead camera saw a mosquitofish move to attack the tadpoles, the robot fish simulated its own attack on the mosquitofish.