Squirrel poop is usually about the size and shape of a dry kidney bean. It is usually dark brown, but can also be red, green, or black. The consistency of squirrel poop can vary, depending on what the squirrel has been eating.
If the squirrel has been eating mostly nuts and seeds, the poop will be mostly solid. However, if the squirrel has been eating mostly fruits and vegetables, the poop will be looser and more watery.
Regardless of what the squirrel has been eating, though, all squirrel poop contains indigestible materials such as fur, bones, and nutshells.