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 ...

CHICAGO — Tickling rats to make them chirp with joy may seem frivolous as a scientific pursuit, yet understanding laughter in animals may lead to revolutionary treatments for emotional illness, ...