White squirrels are almost always a white version of the eastern grey squirrel. There are a few types of genetic aberrations that cause the white coats. The first is albinism, caused by a mutation on a gene that codes for pigmentation. Albinos have red eyes. The other is a white morph, caused by a different gene. It is a naturally occurring trait of eastern grey squirrels that is very, very rare. In our study, we’re trying to figure out just how rare.