Cellar Spiders: Identification and Management

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.

Meet the Cellar Spider

These harmless spiders, sometimes referred to as Merry Widows or Daddy Longlegs, are pretty easy to spot. A large 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. Occasionally, you might even see one carrying a clutch of 15 to 20 translucent eggs in its mouth.

Where They Live

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

Myth vs. Reality

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. However, don’t let that distract you from what’s truly amazing about them.

Spider Superpowers

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 descends 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 and Management

Cellar spider infestations often begin 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 may make their way into the house, where they can thrive on the occasional gnat or other unfortunate insect.

Keeping Them at Bay

The best way to manage cellar spiders inside your home is with a vacuum cleaner. Using the vacuum hose to remove the web effectively eliminates 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.

Peace of Mind

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, especially when you know how to get rid of cellar spiders efficiently.