There are five pseudoscorpion species endemic to Ascension, one of which is the largest in the world. This species, Garypus titanius, has Boatswain Bird Island as its home and, along with another species of pseudoscorpion, is found nowhere else. Garypus titanius hunts at night for insects on the surface of the guano. It is likely that a lack of predators resulted in the species becoming so large.