If you want to study how animals see, a little ingenuity is required. Last year, scientists from the University of Minnesota strapped 3D glasses to cuttlefish and showed them an underwater video of shrimp, to work out how they judge distance when attacking prey (Feord et al, 2020). The cuttlefish saw shrimp moving along in slightly different positions with each eye, the same technique used in 3D movies. When the researchers varied the spacing between the shrimp images, in a way that would make them seem nearer or further away to a human wearing 3D glasses, the cuttlefish adjusted their striking distance before lunging at the shrimp. The Minnesota team concluded that, contrary to expectations, cuttlefish use stereopsis, just as humans do.