Eastern Grey Squirrels are omnivores, and as such eat a variety of food, including various parts of many different tree species, plants, fungi, bird eggs and nestlings, frogs, bugs and bones. Squirrels store food in a process known as scatter hoarding.
Squirrels feed from various parts of many different trees. They seek out the nuts, flowers and buds of all varieties of oak trees, 10 species of hickory, pecans, walnut and beech trees. In maple, mulberry, hackberry, elm, horse chestnut, wild cherry, dogwood, hawthorn, black gum, hazelnut, hop hornbeam and gingko trees, squirrels go after the fruits, seeds bulbs and flowers. The seeds and pollen clusters of evergreen trees, such as cedar, hemlock, pine and spruce, are also consumed by squirrels. Squirrels can also eat fungi.
In the winter, squirrels go after crops, such as corn and wheat, so they do not starve.
However, squirrels are omnivores, so they also eat meat. Insects are often eaten in the summer, and scientists theorize it is especially important for juvenile squirrels to eat insects. Squirrels also eat bird eggs, nestlings and frogs. Cannibalism has even been reported among squirrels.
Squirrels store food for winter in small, randomly placed clusters they then locate by smell and memory.