The eastern mouse spider, Missulena bradleyi, is endemic to the east coast of Australia. Eastern mouse spiders are often mistaken for Australian funnel-web spiders. Their fangs often cross over while those of funnel-webs remain parallel, and the latter often have a drop of venom on their fang tips.
There are 11 known species in the mouse spider genus, all but one of which are indigenous to Australia. The name derives from an old belief, now known to be false, that the spiders dig deep burrows similar to those of mice.
There is evidence that the bite of a mouse spider is potentially as serious as that of an Australasian funnel-web spider; however, recorded envenoming by this spider is rare. Funnel-web antivenom has been found to be an effective treatment for serious bites.
Mouse spiders are medium-to-large specimens, which range in length from 1 cm to 3 cm. Their carapace is glossy, and they have high, broad heads, with eyes spread out across the front of the head. They have short spinnerets, located in the rear of the abdomen. Mouse spiders exhibit sexual dimorphism, with female spiders being all black and male spiders having species-specific colouration. The male eastern mouse spider has a bluish patch on its abdomen.