Nuts: Acorns, walnuts, hazelnuts, hickory nuts, pecans, and peanuts are all popular food sources for squirrels.
Seeds: Sunflower seeds, pumpkin seeds, and various grains are also eaten by squirrels.
Fruits: Squirrels may consume berries, apples, pears, peaches, plums, and cherries, among other fruits.
Leaves: Squirrels sometimes feed on young, tender leaves of various plants and trees, especially during the spring and summer.
Buds: Tree buds are a nutritious source of food for squirrels, particularly during the winter months when other food is scarce.
Flowers: Some squirrel species may eat flowers, especially the nectar and pollen of certain blossoms.
Insects: Squirrels may prey on insects such as grasshoppers, crickets, beetles, and caterpillars.
Eggs: Squirrels may occasionally raid birds' nests for eggs.
Nestlings: Some squirrels have been known to consume baby birds or small animals if the opportunity arises.
It's worth noting that different species of squirrels have their own specific dietary preferences and adaptations. For instance, some species are highly dependent on specific types of nuts or fruits, while others are more versatile in their feeding habits. Some squirrels, like the flying squirrel, are even known to consume mushrooms as part of their diet.
Overall, squirrels' diets are quite varied and they are opportunistic eaters, taking advantage of whatever food is available in their environment.