Mouse Spider

Mouse spiders are robust, ground-dwelling mygalomorph spiders found across Australia, related to the trapdoor spider group. Their common name likely stems from an old belief that they could dig burrows as quickly as a mouse, though the name is more folklore than accurate description of their actual behavior.

Males and females differ noticeably in appearance: females are typically dark, glossy black or brown and heavier-bodied, spending virtually their entire lives underground, while males in several species have a distinctive bright red, orange, or blue head and enlarged jaws, making them far more conspicuous when they leave their burrows to search for mates.

As mygalomorphs, mouse spiders have downward-striking fangs rather than the pincer-like fangs of true spiders, and they are related to Australian funnel-web spiders, sharing a similar burrowing lifestyle.

• Stout, heavily built body with a glossy carapace, typically dark brown to black
• Males often display a bright red, orange, or bluish head region contrasting with a darker abdomen
• Large, robust jaws (chelicerae) positioned to strike downward, characteristic of mygalomorph spiders
• Short, thick legs adapted for digging rather than running
• Lookalikes include Australian funnel-web spiders, which share a similar burrowing body plan but lack the mouse spider's often colorful head

Mouse spiders are widespread across Australia, occupying burrows dug into soil in grasslands, woodlands, floodplains, and even suburban gardens. Burrows are typically lined with silk and may have a thin, camouflaged trapdoor or an open turret entrance, depending on the species and habitat conditions.

Females are highly sedentary, remaining in their burrows for most or all of their lives, ambushing passing invertebrate prey near the entrance. Males become wanderers during the breeding season, particularly after rain, leaving their burrows to search the ground for females, which is when they are most often encountered by people. Mouse spiders can defensively rear up and display their fangs if disturbed at the burrow entrance.

Females lay eggs within a silk-lined egg sac kept inside the burrow, guarding it closely until spiderlings emerge. Young spiders disperse from the natal burrow to dig their own, growing slowly over several years through repeated molts, as is typical for long-lived mygalomorph spiders. Females may live for many years within a single burrow, while males typically die not long after reaching maturity and completing their mate-searching wanderings.