Ground squirrels are either herbivores, which eat only plants, or omnivores, which eat both plants and animals. Different species eat different diets, depending on their habitat.
Herbivorous ground squirrels, such as the California ground squirrel, feed on grasses, herbs, seeds, nuts and grains, according to the University of California. Ground squirrels in desert environments might also feed on barrel cacti, mesquite beans and prickly pear fruit, states the Arizona-Sonora Desert Museum.
Omnivorous ground squirrels, such as the thirteen-lined ground squirrel, eat the same plants as herbivores, but they also include animals in their diet. This includes insects, insect eggs, earthworms and small mice. They may also eat other ground squirrels.
Many communities consider ground squirrels to be nuisances due to their diets and habitats. While foraging, ground squirrels eat seeds and destroy young plants in gardens. They might also kill trees by eating the bark. In addition, burrows can dry out and kill plant roots, and the holes they dig create hazards for operating machinery, including lawn mowers.
In many cases, people can trap or kill ground squirrels to remove them from the property. However, some states consider some species of ground squirrel to be protected. For example, in Pennsylvania, the thirteen-lined ground squirrel is considered threatened, and property owners must get a state permit to trap or kill them, states the Internet Center for Wildlife Damage Management.