Squirrels are a type of rodent with bushy tails and a preferred habitat of woodlands. They are agile climbers and spend most of their time up in the branches of trees. Because they have a habit of leaping from limb to limb, squirrels have acute vision and excellent reflexes. This also helps them escape any predators who think they would make a tasty snack.

It might make sense for squirrels to eat leaves, but they actually can not digest cellulose. Cellulose is the material in the cell walls of plants, which means greenery of any sort is essentially useless to squirrels. So, if they can't eat plants, what do squirrels eat? They're still herbivorous, so most squirrels eat a protein-packed diet of nuts, pine cones, and seeds. They also eat fruits and mushrooms when they can find them. The diet of a squirrel depends mostly on its species, age and the season.

Squirrels, like most rodents, are born hairless, blind and without teeth. They are helpless for around two months, during which time their mother takes sole care of her litter. The mother squirrel nurses her young on milk until they are weaned and able to forage for themselves. Orphaned baby squirrels are best left under the care of a professional, but they can be raised by humans successfully. Some people even keep them as pets, although they are always wild animals and can be a handful. It's very important to keep a baby squirrel warm with a heat lamp. Once it is warm, first give it some Pedialyte with a needle-less syringe; the baby should suckle as much as it needs from the opening. It's important that you do this step first, before giving it milk, to rehydrate the squirrel. A hydrated baby squirrel will be a healthy pink color. To feed the baby squirrel, mix up a formula of one part water, one half part Esbilac powder and one fourth part heavy whipping cream. It's important that you use the Ebsilac powder, as most other milk substitutes will do more harm than good to a baby squirrel. Feed the squirrel as much as it will suckle six times a day until it has a full set of teeth.

The flying squirrel is specially adapted for traveling across treetops with flaps of skin attached to both of its arms and down its body. These flaps allow it to glide through the air for up to 300 feet. At night, they fly through the forest and onto the ground, foraging for bugs, nuts and fungi. What type of nuts they eat depends on their location, but they often dine on acorns, pecans, walnuts and hazelnuts, similar to what you might find in a grocery store. Flying squirrels also eat birds' eggs, slugs, flowers and even tree sap. The act of gliding as a means of travel helps them save energy, which allows flying squirrels to be a bit more picky about what they eat than their cousins.

Squirrels' food sources mostly disappear during the winter, so they have to prepare beforehand. They spend summer and fall building up fat, and as the days begin to shorten they start to hoard away food. Squirrels accumulate several small caches by burying nuts in the ground in specific locations. Contrary to popular lore, they remember the location of their food stores with high accuracy and will methodically visit each as the winter progresses. Surprisingly, the worst part of the year for squirrels is spring, when their caches sprout into plants and their primary food sources haven't had time to grow. Squirrels subsist during this period on blooms and green shoots, digesting what they can until their options start to increase again. Thankfully, they have all summer and fall to become fat and happy once more!

A What Do They Eat? project.