House Spiders: Causes, Bites & Control


House Spiders (Parasteatoda tepidariorum) popular as the American house spider or common house spider are classified under the Parasteatoda genus.

  • House spiders mainly live in cosmopolitan areas and are described as synanthropic meaning they live near and in human dwellings.

House spiders are largely found indoors (in the house). Also, a spider and its webs will prove to be a nuisance in the house – which makes homeowners classify it as a challenging pest.

  • You mainly find house spiders in Canada and the United States but they are also in other areas worldwide.

In this article, I will outline the facts, physical appearance, and behaviors of the house spiders. 

Let’s dig in!

Identification of the House spider

The house spiders will take shelter in man-made structures such as your home barns and sheds.

  • So if you noticed many cobwebs around the house, then house spiders must be this first suspect.

The spiders have a bulbous abdomen and produce uniquely-tangled webs. 

1. Body Shape

The female House spiders have an elevated (almost spherical) abdomen and they measure about 5 mm to 8 mm in length.

  • On the other hand, the male house spiders have abdomens that are elongated and their body length is about 3.7 mm to 4.8 mm.

The spider will appear grey or brown but will have some dark Chevron markings on its body.

The eggs of a house spider hatch in one week leaving it to go through different Instar development.

  • The female house spiders will go through 7 instars while the males will go through 6 instars.

The ballooning process will then take place – it involves dispersing the spiderlings from the silk threads to other habitats.

The adult house spiders can live 4 for a year or more.

These adults will be brown or yellow in color with their abdomens being Grey (dark and brown-banded legs) and having white marks.

  • Another differentiating characteristic of the house spiders is that the males and females can live together and thus mate many times.

2. Color

House spiders are generally around or yellowish Brown in color.

  • Its abdomen is dirty white in color and has a number of dark stripes that meet at an angle.

First, on reproduction, a female house spider will lay roughly 250 eggs that will be wrapped in around (brownish) silken suck that is shaped like a flask.

  • In its lifetime, the house spider will produce 3700 + eggs that will be put into about 15+ silken sacs.

The house spiders are non-threatening and small in size. The bites are painful but then it will only bite for self-defense.

3. Legs

Spiders have eight legs with an elongated bodies.

  • So the characteristic color of the house spiders is yellow-brown or brown.

However, its legs will have dark-colored rings but will still be largely brown.

The eight-legged arachnid has two body segments and lacks both an antenna and wings.

The house spider has 2 palps (pedipalps or appendages) in front of its legs.

If you have noticed some house spiders that have long legs, then outside these are the cellar spiders mainly found in the basements and cellars – damp and dark areas.

  • In fact, due to their thin and long legs, people refer to these cellar spiders as “daddy longlegs”.
  • Canada and the United States have about 20 species of these cellar spiders.

On comparing the common house spider with brown recluse – here’s my take;

  • A sure way of identifying the brown recluse is with its eyes -they have six eyes as opposed to 8 most spiders.
  • The Brown recluses abdomen lacks markings that you will find in the common house spider and also they have smooth legs.

The brown recluse will also mainly occupy the warmer, darker, and quieter location where they will feed and reproduce.

3. House Spider Habitats

House spiders generally love and hide in dark places where they can easily trap insects (such as flies and bed bugs) and camouflage from predators.

  • In the outdoor spaces, the house spiders will largely hide under leaves and around windows, particularly around light sources that tend to attract insects.
  • In the indoor spaces, house spiders will mainly hide in crawl spaces, garages, basements, window frame angles, inside closets, under furniture, and in the upper corners.

Finally, in the warehouse, the house spiders will hide in corners around those that are always open.

The house spiders select the location of their webs through trial and error.

  • Therefore, the spider webs may build up very fast and also attract a lot of dust in a short time – you’ll also see many spider droppings

Controlling The House Spiders

House spiders are generally not dangerous but they make many humans fearful.

  • So to maintain your peace at home and avoid possible venomous attacks you need
  • to control the spiders in the house.

1. Spray Spider Insecticides

Spray the house and the surrounding structures with insecticides that are formulated for spiders.

But since the spiders have long legs, it is important to ensure that the spray touches the spider’s body directly.

  • However, avoid squashing the spiders since this could lead to the fastest production of spider eggs and spiderlings will be distributed all over.

If the space under consideration has some cracks, then you should spray on them since spiders can hide inside there.

  • Since the crack space is small, then the spray chemicals will easily get into contact with the spider’s body.

2. Remove Possible Pest Food Sources

Spiders don’t eat human food but other pests and insects will and so it is important to remove the foods.

  • If the best and various insects are well fed, then the spiders will also be full and hence reproduce better.

So clean up the various scrubs and open food sources that may be lying around.

I advise that you keep all the food containers well sealed, wash the counters, and wipe all the food crumbs.

Doing such cleaner consistently we’ll keep off the insects since they have less food – this will also reduce the spiders in the house.

3. Adopt Great Pest Prevention Methods

The house spiders primarily feed on bugs and insects that get into the house and hence it is important to prevent their entry.

  • Some of the entry points into your house will include screen tears, crevices, cracks, or drainages.

Some of the excellent pest prevention methods you can adopt for this include repairing the leaks or broken screens and sealing up the cracks.

  • This will limit the foods (insects and bugs) that are available for the spiders.

4. Use Glue Traps

For areas of the house where you are sure to have spiders walking around, I advise that you set up some quality glue traps.

  • The glue traps must be set up in places such as the basement or ceiling where there is darkness.

Spiders have great vision and they will see insects that are trapped and will attempt to catch them.

  • As the spider attempts to eat the trapped insect, it will also be trapped by the glue.

But remember to position the glue traps in quiet, and dark places like near the beds and around baseboards.

5. Vacuum the house thoroughly

To prevent the entry and fast reproduction of spiders, I advise that you vacuum the house thoroughly.

  • Remember to vacuum the hard-to-reach places such as the door frames, window frames, and baseboards.

The vacuum machine will help kill the live spiders while sucking up the egg sacs and the spider webs.

  • The vibrations, chemicals, and trauma caused by the vacuuming process will kill the spiders fast.

Male spiders have real height inside crawl spaces, basements, closets, under furniture, and in the ceiling corners.

How Dangerous Are The House Spiders?

House spiders aren’t dangerous humans but will cause considerable nuisance and pain in case they bite – just like the wolf spiders.

So these spiders won’t cause considerable health damage to humans but they may make the house or various spaces feel unwelcoming.

  • The spiders will trigger nervousness among the family members and sleeping off the webs will also be a demanding task.

You can do the spider control as a DIY Project but it is best you hire a professional with knowledge of the various spiders.

  • You can prevent the entry of spiders and various insects by sealing up cracks using some silicone-based caulk.

If house spiders have gained entry into the house, you should vacuum the spaces to remove the webs, egg sacs, and adult spiders.

Avoid using a broom only in the cleanup since most of the adult spiders will escape. 

Conclusion

House spiders may not pose a great health risk to humans (and like spiders such as the black widow spiders) but they are bites are painful.

  • Also, their presence may cause nervousness among family members.

So it is important that you adopt effective prevention and control of the house spiders.

  • Prevention will involve filling up cracks that may allow spiders and insects to get into your spaces.
  • You can control the house spiders by using spider bombs, spider sprays, and vacuuming. 

Cheers!

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