Prairie dogs tend to be celebrated for their larger ecological virtues. In the grasslands across the central and western United States, their intricate underground colonies—called prairie dog towns—create shelter for jackrabbits, toads, and rattlesnakes. The bare patches of ground created by their grazing and burrowing attract certain insects that feed a variety of birds. And prairie dogs themselves are a key food source for everything from coyotes to hawks to endangered black-footed ferrets.

“These animals support at least 136 other species through their various activities,” said Kristy Bly, a WWF senior wildlife conservation biologist. “They’re basically the Chicken McNuggets of the grasslands.”

But these small, chubby-looking mammals are also fascinating in their own right. Check out these facts for a glimpse into their strange, surprisingly complex world.