Opossums are a common nuisance species because they are opportunistic, and will take advantage of human homes, sheds, decks, etc in order to live and steal food. They are marsupials, and the young grow in a pouch in spring. I commonly find them in the attics of homes, and they are also a common dead animal extraction target. They are interesting: they have the most teeth of any mammal (50), a prehensile tail, opposable thumbs, the male has a bifurcated penis, they can eat almost anything, and they have incredible immune systems, all of which make them great survivors, despite their tiny brain.