With their round cheeks, probing little paws, and fuzzy bodies that fit perfectly in your palm, domesticated hamsters are popular pets. But lesser known are the 26 species of wild hamster that scamper through parts of Europe, Asia, and the Middle East—all of them cute, but not necessarily cuddly.

The aggressive European hamster, for instance, will leap at and bite any person that tries to touch it, says Mikhail Rusin, a researcher at the Kyiv Zoo in Ukraine. “Even those born in captivity, when they grow up, are not tame,” he says.

Ferocious as it is, this one-pound rodent can’t hold its own against threats such as climate change, agriculture, and light pollution. Those forces likely have contributed to wild hamster