One of the key mechanisms of Toxo's behavior is that it can penetrate the brain of rodents and make them sexually attracted to feline urine -- the point is to facilitate the reproduction of the parasite which can occur only on feline intestines.
They infect both female and male crabs and completely subvert their biochemistry, to the extent of feminizing the males. They then lay their own eggs in the crab's carapace, the way the crab normally would, and the crab--male or female--behaves as if it was carrying its own eggs.
One of the key mechanisms of Toxo's behavior is that it can penetrate the brain of rodents and make them sexually attracted to feline urine -- the point is to facilitate the reproduction of the parasite which can occur only on feline intestines.