These charismatic, rabbit-sized rodents live on North America's prairies and open grasslands in only a fraction of their former numbers. Prairie dogs live in underground burrows, extensive warrens of tunnels and chambers marked by many mounds of packed earth at their surface entrances. Burrows have defined nurseries, sleeping quarters, and even toilets. They also feature listening posts near exits, so animals can safely keep tabs on the movements of predators outside. Prairie dogs spend a lot of time building and rebuilding these dwellings. Other animals benefit from their labors. Burrows may be shared by snakes, burrowing owls, and even rare black-footed ferrets, which hunt prairie dogs in their own dwellings. animals.nationalgeographic.com /animals/mammals/prairie-dog.html