Red-headed Mouse Spiders can be found all over mainland Australia, making them the most distributed of all the Mouse spiders.
Males and females of the species are so vastly different in appearance that they were originally thought to be completely different species.
Female red-headed Mouse spiders are large, stout spiders with short legs and tend to be brown to black all over, with red-tinged jaws. They are also typically much larger than the males.
Males on the other hand, have a bright red head and jaws, and a blue to black abdomen. They have thinner, longer legs and are much smaller than females.
While the Red-headed Mouse spider is typically found near waterways and in burrows in the ground, they can also be found in suburban yards in burrows that can be 30 cm deep. The females tend to remain in or near their burrows throughout their whole life and are sedate spiders who are rarely aggressive.
These creepy crawlies mainly prey on insects and other small spiders but will also occasionally feed on small vertebrates such as frogs and lizards.
The Red-headed Mouse spider is itself hunted by parasitic wasps, scorpions and centipedes.
Sexual maturity usually takes around four years, with males often being found wandering for females during the day, more commonly after rainfall.
Males will rarely wander during daylight hours and will usually hold out their long pedipalps (carrying their mating organs) presumably seeking pheromones from nearby females.
Once the male has located a female or her burrow, he will tap the ground until the female emerges. If she is receptive, the male will follow her into her burrow where mating will occur.
After mating, the female will lay 60 or more eggs in an egg sac that she places into a chamber off the main shaft of her burrow. The spiderlings hatch from the egg sac over summer and remain with the mother into autumn when dispersal occurs.
The spiderlings of the Red-headed Mouse Spider disperse by ballooning, a rare technique among mygalomorphs. This explains the relatively wide distributions of the Red-headed Mouse Spiders compared to other mygalomorph species.
Source: https://australianmuseum.net.au/learn/animals/spiders/red-headed-mouse-spider-missulena-occatoria/
