trapdoor spiders (order Araneae, suborder Mygalomorphae) Spiders of the families Antrodiaetidae, Actinopodidae, and Ctenizidae, which have three tarsal claws and a rastellum. Most species are 1–3 cm long and live in a silk-lined tube dug into the ground, with a silk lid. Passing insects are attacked and pulled into the tube with great rapidity, and the tubes are enlarged as the spiders grow. Trapdoor spiders are found in the Americans, Africa, and Australia.

trapdoor spiders Spiders of the families Antrodiaetidae, Actinopodidae, and Ctenizidae (order Araneae), most species of which are 3 cm long and live in silk-lined tubes dug into the ground and covered by silk lids. Passing insects are attacked and pulled into the tubes with great rapidity, and the tubes are enlarged as the spiders grow. Trapdoor spiders are found in the Americas, Africa, and Australia.