With a diet mostly comprised of nuts, seeds, flowers, herbaceous plants, and fungi, pest squirrels prefer to inhabit forested areas throughout the contiguous United States, Northeastern Mexico, and Southcentral Canada. Some species of Nearctic squirrels have also been introduced to European countries like Italy, Scotland, England, and Ireland, where they are considered invasive pests.
More information about what squirrels eat.
Though most squirrels orient themselves around the presence of trees, their chosen nesting sites vary from species to species. Fox squirrels, for example, prefer oak, pine, and mixed forests where the trees are widely spaced. Conversely, eastern gray squirrels live in forests where the trees allow for travel among the upper layer of leaves and branches, as they rarely move along the ground. Most species of squirrels build nests out of leaves and branches or use tree cavities as shelter.