Your home is their home, but this doesn't mean you have to welcome them as guests. Let's look at a few things you can do to encourage your tiny housemates to make themselves scarce.
House spiders are well adapted to the constant temperature and limited food found in your house. They lay eggs in places where they aren't likely to be disturbed, such as crawlspaces, attics, or behind your dresser. They also nest under your eves and siding, and all around the foundation. This is especially true if you have lots of bushes or trees outside.
By periodically decluttering and sweeping out the dark corners of your home, you eliminate those spots as potential nesting places and discourage spiders from hanging around inside. The first step is to identify places where spiders like to get comfortable.
Look for dusty, out-of-the-way places like the backs of closets, or anywhere you'd expect to find insects. Some spiders are attracted to warmth as well, so check around water heaters and other large appliances. Cobwebs are a dead giveaway, so get rid of them.
Stop the Gaps
A spider can squeeze its body through surprisingly small holes. Your home probably has a number of these openings. Scan every room for loose outlet covers and holes around water and electrical fittings, and close them up.
Examine window screens for holes. Spiders and insects can enter around loose-fitting frames, so check to make sure your screens fit snugly and are free of holes. Repair or replace any screens that are no longer up to the task.
You can also check exterior doors for openings a spider might take advantage of. Here's an easy trick: close the door and shine a bright flashlight from the other side all the way around the seam. If any light comes through, chances are, a spider can too. You may want to install weather stripping or door sweeps to seal off the gaps. As an added bonus, you'll be reducing cold air drafts and saving on your energy bill. Feels good, doesn't it?
Don't Feed the Spiders
Spiders are voracious eaters, consuming more insects than just about any other animal in the world. Our homes are often visited by flies, mosquitos, earwigs, moths, and a host of other insects, especially in warmer climates. In addition to fixing screens and doors, you can keep insects at bay by being extra tidy in the kitchen. Avoid keeping food out on the counter, or dirty dishes in the sink. Sweep and vacuum floors to pick up dust, which can attract dust mites.
By eliminating these pests, you can eliminate many of the spiders that prey on them. Spiders aren't likely to stick around when there's nothing to eat, and will move on to the insects they find under and around your house.
What's That Smell?
Spiders are thought to dislike certain fragrances, so the strategic application of lavender or peppermint essential oils will discourage spiders from loitering, effectively creating an invisible barrier. You can also try lemon, tea tree, cinnamon, or citronella oils. Pick a scent that you find pleasing, since you'll likely be putting this stuff all over your house.
To apply, simply fill a small spray bottle with water. Add a few drops of the essential oil of your choice, plus a drop or two of dish soap. Oil and water don't mix, of course, but the soap will break the surface tension of the water enough to allow them to blend together. The resulting mixture should smell fairly strong, but not overpowering. Apply the mixture every couple of weeks on window sills, door jams, and anywhere else you don't want spiders to tread.
Follow these instructions to keep spiders out of the clean, well-lit rooms that you use, and let them have the dark, dusty spots that you don't. After all, there's no place like a crawlspace for a spider.