Some friends of my brother came across what was thought to be the remains of a dead animal, but turned out to be something else. As you see by the first photo it actually looks like remains. But take a look at the next photo as the tiny bunnies are revealed. (click pictures for larger view)
The female rabbit builds the nest which begins with nothing more than a scrape followed by grasses, other plant material and then fur that she removes from her own belly. Typical litters consist of 3-5 young and each time the female leaves the nest she covers them returning at night to feed them. After 3-4 weeks they are mature enough to leave the nest and take care of themselves. A discovered nest should be left covered and undisturbed. Human scent may cause the female to abandon them. If you ever come across what appears to be the fur of a dead animal, think twice about disturbing it. It just may be a nest of bunnies.