Across the United States, a patchwork of bans and crackdowns reveals the hidden dangers of keeping some animals as pets.

A baby howler monkey clung to the back of an older male monkey, its tiny fingers grasping fur. But they're not related and not even the same species. Scientists spotted surprising evidence of what ...

A capuchin named Joker started the apparent trend, leading researchers to suspect "there was something a little quirky about him, or that he was kind of lonely in a way.” Reading time: Reading time 3 ...