Cellar Spiders

If you're anything like me, spring cleaning doesn't really kick off until the sun starts shining regularly. And when it does, one of the most common critters you'll encounter is the cellar spider.

These harmless spiders, sometimes called Merry Widows or Daddy Longlegs, are pretty easy to spot. A big one is about the size of a small popcorn kernel, with long, hair-like legs that span about the diameter of a quarter. You’ll often find them hanging upside down in a tangle of web in the upper corners of rooms and garage ceilings. Sometimes, you might even see one carrying a clutch of 15 to 20 translucent eggs in its mouth.

In the wild, cellar spiders typically hang out in leaf litter or under logs, branches, and stones. Basically, any horizontal surface where they can build a web and hang upside down to wait for prey.

These spindly-legged spiders are the stuff of legend. There's a myth that they're the most venomous spiders on the planet, but their fangs are just too short to bite us. In reality, their venom is much weaker than that of many other spiders. But don't let that distract you from what's truly amazing about them.

Despite their weaker venom, many cellar spiders prey on spiders that are much larger and more venomous. They manage this with webs that aren’t even sticky! Their webs are made of disorganized strands that act as both a snare and a telegraph. When an insect tries to pass through, it gets slowed down by the strands. The web's vibrations alert the spider, which then starts gyrating wildly to further ensnare the prey. Once the prey is slowed down enough, the spider climbs down and uses its long legs to cast numerous strands of silk over it. After encasing its victim in silk, the spider bites and injects its venom. It might feed immediately or save the meal for later.

Cellar spider infestations often start in the garage, where they can hitch a ride on vehicles and lawn furniture. Garage doors that don’t seal tightly allow ants, sowbugs, flies, and other insects in, providing a steady food supply for the spiders. With plenty of food, their population can boom in just a few months. Eventually, some make their way into the house, where they can survive quite well on the occasional gnat or other hapless insect.

The best way to manage cellar spiders inside your home is with a vacuum cleaner. Using the vacuum hose to take down the web removes the spider and its eggs. In the garage, a shop vac works well. If you have a lot of stored items or places that can’t be reached with the vacuum hose, you might need to treat for them. An aerosol insect spray is preferred over ant and roach killers because the evaporating mist can reach into voids that are otherwise inaccessible.

With that chore behind you, you can sleep peacefully knowing that the most venomous spider on earth isn’t the one hanging out in the corner of your bedroom ceiling.