Turtles have a habit of eating their own stool. This behavior seems disgusting, but is quite natural for turtles. They also shed scales off their shells. It is important to make sure that the peelings are transparent. If the scutes come off, the turtle is not sick.
Scutes tend to fall off when the turtle is growing.
They need to make room for new ones. Make sure if your turtle is shedding skin, keep an eye on them. You might be feeding them too much food, thus causing your turtle to grow too quickly. This loose skin has a habit of clogging up your filter, be prepared to clean your filter at least once a week, maybe even twice, depending on water quality. For more information on this subject try Shedding and Scutes on Valerie's Turtle Information Page.