Years back, hermaphrodite animals looked like a few outcasts on the list of animals but today we have discovered a whole lot of them and we keep finding a lot more. We have learned that these species have a purpose for being hermaphrodites and they have either an advantage or reason for being one. About 1/3 of the non-insect animal species are hermaphrodites. Still, you or I do not see them often because the animals we are familiar with, like birds, dogs, and other mammals, aren't hermaphrodites.