Trap-door spiders are to be found just under the surface of the earth. They belong to the class of spiders called mygalomorphae which includes the bird-eating spiders on the tropics. All these spiders tend to be rather large they have four lungs instead of two, and their jaws work vertically instead of sideways.
The trap-door spider has perfected the art of burrowing underground. Its jaws are provided with a special row of teeth with which to dig out its home. It lines its burrow with silk and makes a trap-door consisting of layers of silk and earth. The outside of this door is coated with moss or some other form of camouflage. The spider lies in wait behind its trap-door, darting out to seize its prey.
Trap-door spiders are widespread throughout the hottest regions of the world, with comparatively few in the temperate zones. Specimens of up to four and a half inches have been found. It is estimated that some may live up to 20 years.