Not all raccoons harbor Baylisascaris. But enough of them do to pose a significant health threat to humans. Most infective eggs that are accidentally consumed are eaten by small rodents or birds that sort through raccoon waste looking for seeds and food remnants. That intermediate host is often a deer mouse (Peromyscus) like the one I drew, or a cotton rat. But just about any warm blooded creature that accidentally consumes an infective egg is susceptible. The worm never develops into an adult in these small creatures. Instead, it forms a larval cysts within their bodies that often persist until the small animal is eaten by another raccoon. The larva then goes on to develop into an adult Baylisascaris worm within the new raccoon's intestine. The infective egg can also be accidentally eaten by a raccoon without first passing through an intermediate host. When that occurs, the larva hatches and goes on to form an adult parasite in that raccoons intestine. Should a human being accidentally consume and infective egg(s) that individual might develop a case of visceral or neural migrans, an inflammatory process that occurs as the body attempts to destroy the larval parasite.