Cleaner wrasse have revealed a remarkable new side of fish intelligence. Marked with fake parasites, they used mirrors to inspect and remove the spots—far faster than seen in earlier tests. Even more ...

Learn how cleaner wrasse used a mirror and even dropped food to test their reflections, a behavior linked mostly to mammals.

In the current study, the scientists observed new behaviors during a series of mirror test experiments, a widely used method ...

In the new experiment, roosters made fewer alarm calls, meant to warn peers of predators, when placed in front a mirror versus when standing near another rooster. Stefano Spaziani / picture alliance ...