The Hills Have (Eight) Eyes: House Spiders in Illinois

 In Blog

Did you know that, even now, you’re no more than eight feet away from the nearest spider?

We’re not trying to scare you – Halloween was last month. It’s just that most people think the minute cold temperatures roll around in the upper Midwest, that means they no longer need to worry about pest control for their Illinois homes or businesses. However, as we proved in our previous article about overwintering pests, plenty of them manage to survive below-freezing temperatures by coming indoors.

If you happen to see a spider skittering across your kitchen floor in the middle of November, you might imagine it’s yet another pesky intruder. But what if we told you that spider may have been there as long, if not longer, than you?

Why Are There Spiders in My House?

The thing most people fail to understand about spiders is that they’re not insects; they’re arachnids. There are several differences between these two classifications – for example, one has six legs, the other eight – but the main difference is that insects want to eat you out of house and home, while arachnids want to eat those insects. They also just want to be left alone; unlike other common Illinois household pests, they live very solitary lives and try to stay out of sight as much as possible.

In fact, only about five percent of the spiders you see inside have ever set foot outdoors. Of the other 95 percent, there is a specific subset of spiders called “house spiders” that has lived symbiotically with humans since Roman times and has adapted to life indoors, with a constant climate and very poor food and water supply (at least when compared to the outdoors).

As usual, you can thank global commerce for bringing them from their native Europe over to North America. Once here, they began colonizing structures by hiding in egg sacs carried on furniture, building materials, and other items brought indoors without cleaning or inspection. They then spent their whole lives on, under, or within these buildings, often without the occupants even noticing.


Why Am I Just Now Noticing These House Spiders?

Because they have no other choice. If they had their way, they’d be content to live out their days in the shadows munching on stray insects – an excellent source of free pest control. Chances are, the house spiders you find in the fall and winter months are males that originally hatched in the spring, and now they’re competing for two things: food and mates.

Often, house spiders are found trapped in sinks and tubs, which leads people to assume they’ve somehow come indoors through the drain or plumbing fixtures. In reality, these are simply thirsty house spiders that went looking for a sip of water and got stuck. After all, even spiders must drink to survive, and it’s not like you’re leaving out a dish of water for them like you would for your pets.

Common House Spiders in Illinois

Unlike their outdoor cousins, some of which (like the wolf spider) go hunting for their prey, the majority of house spider species prefer to construct elaborate webs to catch their food. They’re also rarely larger than half-an-inch in size, which makes sense when considering how they’ve adapted to survive with relatively small amounts of food. The following are a few of the most common species of house spiders found in Illinois homes and businesses:

Cellar Spider

Commonly confused with “daddy long-legs” spiders because of their long, spindly legs, cellar spiders have tiny bodies measuring only ¼-inch long at most. Colors range from gray to brown, with distinct bands or chevrons present on their abdomens. Cellar spiders often build their messy, irregularly shaped webs in corners near the ceiling or floor of basements, attics, or commercial warehouses.

Cobweb Spider

These spiders have a larger abdomen in comparison to their heads, giving them a more “traditional” spider shape. Cobweb spiders are considered medium-size for a house spider species, with ½-inch long bodies that can be black or brown. They like to build webs near the floor of crawlspaces, basements, and garages, but will frequently abandon them if they are not productive, leaving behind the cobwebs that give them their name.

Yellow Sac Spider

There are many small- to medium-sized species of house spiders that make web “sacs” about one inch in size to hide in during the day. At night, they emerge to hunt for prey, and will most likely build a new sac somewhere else instead of returning to the original. Because the yellow sac spider is so small – only 1/4-inch in size – the best way to spot an infestation is to look for multiple abandoned sacs around door or window frames, and in corners where walls and ceilings meet.

Yellow sac spiders are one of the most common indoor spiders, and in fact, most bites mistakenly diagnosed as “brown recluse bites” are actually from the yellow sac spider. It makes sense; these nocturnal hunters bite instinctively when touched, and their bites can cause a sharp pain with some localized redness and light swelling. Thankfully, because of their small size and lack of potent venom, they are not dangerous to humans.


How Can I Get Rid of House Spiders?

The same general rules for pest control apply to spider control as well. First, you’ll want to identify the type of spider you’re dealing with. As we said earlier, most indoor spiders are house spiders, and therefore not dangerous. In fact, they’re one of the most “eco-friendly” methods of pest control you can find. But that doesn’t mean you should be forced to live with them.

To prevent house spiders from setting up shop in your home or business, make sure to inspect any boxes or pieces of furniture for egg sacs or live spiders before bringing them inside. You should also take the time to locate and seal any potential entry points around your foundation, walls, or windows. While this won’t do much to curb spiders already indoors, it will cut off their food supply, forcing them to either move somewhere else or die out.

You can also set sticky traps in specific rooms to determine which areas have the most house spider activity. Spiders that walk over these traps will stick to them and die of starvation; however, this is not the best way to control a large infestation. As usual, your best bet is to contact an Illinois pest management specialist like Anderson Pest Solutions that specializes in spider control. We will make use of a combination of techniques that are proven to effectively eliminate spider infestations quickly.


Let Anderson Pest Solutions Take the “House” Out of “House Spiders”

Just because the weather has turned colder in Illinois doesn’t mean you should let down your guard. At Anderson Pest, we believe pest control should be a year-round process, which is why we offer our pestfree365 program to protect homeowners from over 36 different pests – including spiders – all year long. If you’ve found it too hard to live with your eight-legged housemates and want to show them the door, contact us today for a free quote on our spider control service in Illinois.