The red-headed mouse spider (Missulena occatoria) is found almost everywhere in Australia, from open forests to desert shrublands. It is the largest (females up to 24mm, males up to 12mm) and most widely distributed Missulena species, because the spiderlings are wind-dispersed (ballooning). Normally this only occurs with araneomorph spiders, mygalomorph spiders normally disperse by walking.
The spiders dig a burrow up to 55cm deep, with two trapdoors.
While the females are black with a red tinge, the males have a bright red head and jaws, and a gunmetal blue-black abdomen.