Animals that laugh challenge the idea that joy is uniquely human. From rats and chimpanzees to dolphins, hyenas and kea parrots, many species express happiness through laughter-like sounds. These ...

Over millions of years, naked mole-rats have cast away everything underground which uses their energy and isn’t necessary to survive. They hypothesized the chirps might serve a social function.

When two nearly blind naked mole rats encounter each other in a dark subterranean tunnel, it could be a friendly meeting or a moment of potential bloodshed between strangers. The creatures chirp to ...