Here we see an urban squirrel enjoying her pecan while sitting on the top bar of a chain link fence. These little creatures make use of whatever is available for moving about in their environment. The species pictured here is Sciurus niger, the Fox squirrel.
Most people think squirrels just eat nuts. Here we see another urban squirrel enjoying some grass from the lawn. Some folks have trouble with these little fellas raiding their bird feeders, too.
This squirrel is in the top of a pecan tree. If the tree had all its leaves, the color of her underbelly would make her difficult to see. From above, her fur makes it hard for a predatory bird to tell her from the branch she is on.