Prairie dogs are herbivores, so the majority of their diet comes from leaves, roots and weedy flowering plants called forbs. Black-tailed prairie dogs, a common species, get 98 percent of their diet vegetation. The other 2 percent comes from the occasional consumption of insects.
Some plants that black-tailed prairie dogs like to eat include buffalo grass, wheatgrass and rabbitbush. Mexican prairie dogs, another common species, get about 60 percent of their diet from forbs. Forbs include plants such as milkweed, clover and sunflower. They also eat shrubs, grasses and roots or tubers. Both species also occasionally eat cacti, such as prickly pear.