Drunk fish aren’t nearly as afraid of robots. Typically, researchers who want to study anxiety need to be cruel to rodents. An average anxiety experiment will involve training the mice or rats to associate a sound with an electrical shock. If, for some reason, you wanted to use fish as your study system instead, this wouldn’t work especially well for purely practical reasons (namely, moving your fish to a tank where you’re able to give it a shock would probably be anxiety-inducing on its own). So, when an international team of researchers decided they wanted to make their zebrafish anxious, they came up with an alternative approach: robots. They built robotic versions of the fish’s natural predators, a heron and a larger fish, and then set them after the real fish. The robotic predatory fish appeared to be very effective, and caused the zebrafish to seek shelter. The researchers then confirmed that everyone’s favorite anxiety self-medication—alcohol—worked on the fish, as well.