Name: Antrodiaetus montanus

Alias: Trapdoor spider. You may see this large spider during the fall months or after a rainstorm. Under normal circumstances they are actually quite shy. They dig burrows underground and create a cute little trapdoor to keep their little home clean and to deter would-be marauders. They stay indoors all day, only coming out at night to hunt for prey. For this reason they are rarely ever seen, although they are quite common. Males abandon their burrow in the fall in search of mates. Their color can vary from red to brown. Their eyes usually come to a point on the top of their abdomen. They have large palps in front of their mouth that look like extra legs.

Crimes: Bites from trapdoor spiders are rare. If bitten it would be nothing more than a bee sting. Their biggest crime is creeping you out right around Halloween time.

Redeeming qualities: Trapdoor spiders eat a whole list of bad insects all year long and control many pests in agriculture and landscapes.

Sentence: In my opinion this one merits a full pardon, but there are many who would disagree with me when it is crawling across their floor and they forgot to wear slippers. So, if you fall into the second category, feel free to capture it and relocate it. I would not advise that you need to fumigate your entire house, because they really don’t enjoy being indoors. Their food and potential mates are definitely not in your house, and they probably just made a wrong turn.

For more information on dangerous and beneficial bugs, call UI Extension educator Joseph Sagers at 208-745-6685 or email