A kind of North American ground squirrel, of the genus Cynomys ('dog-mouse'). There are five species. They are also known as the prairie marmot and the wishtonwish. They build large communal burrows called towns, and raise a defensive earthwork around them to keep out surface water. They live on roots and insects when they can't get vegetation. From four to six young are born in May.
The black-tailed prairie dog C. ludovicianus is about 30 cm long and heavily built, light yellowish-brown in colour apart from the tail. The white-tailed prairie dog C. leucurus is smaller but otherwise similar except for its tail.
They prefer cattle country because there is no long grass: they can see predators from a distance. Their upright stance when peeking on lookout, as seen in many a nature documentary, gives rise to the expression prairie dogging.