It's easy to smile when you have a squirrel's intellect.

Squirrels are members of the family Sciuridae, a family that includes small or medium-size rodents. The squirrel family includes tree squirrels, ground squirrels, chipmunks, marmots, flying squirrels, and prairie dogs amongst other rodents.
Squirrel, (family Sciuridae), generally, any of the 50 genera and 268 species of rodents whose common name is derived from the Greek skiouros.
Tree squirrels are the types most commonly recognized, often seen gracefully scampering and leaping from branch to branch. Other species are ground squirrels.
Most types of squirrels are vegetarians. They are not picky eaters and will feed on practically any food that's readily available, but they tend to prefer vegetables and fruit. Favorites of the squirrel diet include corn, mushrooms, squash and broccoli. They also enjoy apples, oranges, apricots and avocados.