GIMME SHELTER- Web of spiders? Get rid of those other insects!
Q:The are so many spiders setting up shop in the eaves around my house, especially above my outside deck, where I keep walking into their webs! I destroy their webs, but they build them again the next day. How do I get rid of all these spiders? And how do I know if any of them are dangerous?
A: The presence of spiders is a litmus test for insect activity around your home. If you have an abundance of spiders, you most likely have an abundance of insects, the spider's natural food source. Reduce the attraction of insects to your home, and you'll reduce the number of spiders. Since spiders can travel great distances by "ballooning," in which they send out a tendril of webbing and fly though the air, unless you control the insects around your home, the spiders are sure to return. (Of course, some people actually like having spiders around for precisely this reason– because they eat other, more annoying insects.)
To control insects, make sure your yard and shrubbery are generally clean, that there are no damp spots in your yard, that garbage isn't piling up, or that water isn't lying stagnant in your gutters. You'll also want to reduce the volume of light coming from your house, which attracts insects, and leads spiders to, as you say, "set up shop" in the eaves. If you have alot of glass windows, use shades or make sure to keep lights off or dim when not using them.
As for removing the spiders you have...using a broom or dry mop (one with an extension for hard-to-reach places), you must physically destroy or remove the spiders themselves, not just their webs. You'll also need to destroy their brown groupings of eggs, one of which can produce as many as 200 baby spiders!
While all spiders are venomous, releasing a poison into their prey that paralyzes them and dissolves their innards, most spiders are not dangerous to humans. In addition, the spiders that are dangerous, such as the Black Widow (identified by their shiny black color with red or yellowish hourglass pattern on the abdomen) or the Brown Recluse (yellowish to dark brown with a distinctive violin shaped brown marking on the top of the cephalothorax– the region just behind the eyes), are rare and unlikely to be hanging out in your eaves, or any place where they could be easily found. In 17 years, we've had five confirmed discoveries of the Brown Recluse and fewer than a dozen Black Widows.
Still, for those with allergies or who are at risk of anaphylactic shock, especially young children and the elderly, it's worth being cautious. The Black Window delivers a very, very painful bite, which can lasts for a few days before your body works the poison out. And a venom in the Brown Recluse's bite can leave a permanent scar. While fatalities of healthy adults from such bites are very rare, its best to seek medical attention if a bite occurs. It's also helpful to take the spider specimen to the doctor so it can be correctly identified.