Scientific Name: Missulena occatoria
In a recent case that has baffled scientists, many hundred mouse spiders were captured and removed from a single suburban backyard in Newcastle, New South Wales. Experts from the Australian Reptile Park, the Australian Museum and Sydney,s University of Technology made numerous visits to the garden and in the end the entire backyard was excavated and removed to counter this invasion.
Mouse spiders are closely related to trapdoor and funnel-web spiders but can be distinguished by their pronounced compact, squat shape and huge fang sheaths at the front of the head area. Most species are dark brown or black in colour, although the male red-headed mouse spider has a bright reddish-brown front part of the head or cephalothorax. The body size reaches around 35mm, with the male being distinctly smaller and less robust.
Mouse spiders live in oval burrows up to a metre in length, often constructed in the banks of water courses. The female's burrow usually has a hinged lid and is a branched 'Y' shape. These spiders are common but are very secretive and rarely seen. Heavy rain often forces them out of their burrows and this is when they may be encountered.
The extremely large and robust fangs enable mouse spiders to overpower quite large food items. Even the thickest beetle shell is no match for these efficient weapons. The venom is very toxic and, although no human deaths have been recorded, a bite from a mouse spider should be considered potentially life threatening and medical attention should be sought immediately.
Female mouse spiders spend almost their entire life in their burrow. Male mouse spiders search for a mate once they reach maturity at around four years of age. Mating will usually take place in the female's burrow. After fertilization, the female digs a special side chamber in her burrow and then seals the egg sack inside.