For decades, scientists used a mirror experiment to explore whether animals could recognize themselves. In that test, ...

In theory, a reaction to an out-of-place mark in a reflection is assumed to be evidence of self-recognition for other animals as well. Chimpanzees, elephants, and dolphins are just some that have ...

Learn how cleaner wrasse used a mirror and even dropped food to test their reflections, a behavior linked mostly to mammals. A small reef fish may be doing something scientists once thought was ...