Thaumatogryllus conanti is a nocturnal species of cricket endemic to the island of Nihoa, where it is found in Devil's Slide, a narrow ravine.

Including T. conanti, there are only four known species in the genus Thaumatogryllus, which is endemic to Hawaii.

Another species is found only in lava tubes on the Island of Hawaii.

Usually, larger size makes it harder to escape from predators, but in these cases, there are none.

This insect probably lost the capacity for flight in exchange for larger size.