High Quality Content by WIKIPEDIA articles! Mouse spiders are spiders of the genus Missulena, in the mygalomorph family Actinopodidae. There are 11 known species in this genus, all but one of which are indigenous to Australia. One species, M. tussulena, is found in Chile. The name derives from an old belief, now known to be false, that the spiders dig deep burrows similar to those of mice.