Do rats feel joy? It can be hard to tell, since they can’t exactly greet us with a grin. But now, for the first time, scientists have spotted the rat equivalent of a smile—and it’s all in the ears.

Warmth and positivity shine through this realistic drawing, where a cheerful girl is portrayed with natural expression and emotional clarity. The artwork focuses on capturing happiness through relaxed ...

Mirjam Guesgen* does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond ...