Among various and numerous types of common household pests, spiders occupy a special spot. There are dozens of spider species that would readily prefer stable, controlled environment of a house over the inherent unpredictability and danger of the wild. Also, different species have different environmental preferences, which only heighten the chances that your house will appeal to one of them.
Another complicated issue is the fact that while some spiders are clearly dangerous to humans, many are mostly or completely harmless, and can even turn out to be quite helpful. If you have found out that you are sharing your home with a couple of spiders, you don’t have to immediately run to the phone and hire a team of spider exterminators. First, you should determine what causes for infestation are, what species of spiders you are dealing with, and perhaps try to address the issue yourself.
Causes of spider infestation
A spider infestation can be the result of many different factors, but certain causes are more common. The number of calls for spider exterminators always rises during the cold and rainy seasons. Just like most insects, spiders will always try and seek shelter during the rain, which is always potentially fatal to such small creatures. Being cold-blooded, spiders will also try to hide from extreme temperatures. While many species show good resistance to heat, cold is always a hazard.
In the wild, spiders usually live on or near plants. If you have recently bought a potted plant, chances are that a small spider or a number of spider eggs have “hitched a ride”, so to speak, into your house. If you live in an apartment block, a few spiders may wander over to you from your neighbors.
Generally untidy places with poor upkeep are nearly always safe for spiders, since such places have plenty of small nooks and corners to hide in or build webs on. Small holes are also hard to access by larger creatures. Basically, this is the reason why basements, attics, and ventilation systems are such a favorite among arachnids.
One more likely cause of infestation is abundance of small bits of food such as bread crumbs. Such a food source will attract insects, and insects will attract spiders. Certain small species of spiders may even be helpful to the household, hunting down other insects, as long as the spider population itself is small enough to not be a nuisance.
The most common sites of spider infestation include attics, basements, cars, rarely used closets, any small cracks, secluded corners and air vents, especially near or in kitchens and bathrooms.
Which species of spiders are most commonly found in houses?
First of all, one should know the distinction between hunting and web-building spiders. Hunting spiders do not build webs, instead using their good eyesight and great speed and agility to catch prey. Web-building spiders wait for prey to come to them and get caught in the web. Most spiders found in households are only active at night.
Spiders are generally very shy, prefer to remain hidden, and try to flee if confronted by a larger creature. Only a handful of species are aggressive enough to bite a human, have long enough fangs to pierce the skin, and strong enough venom to elicit a potentially serious reaction. However, people living in warmer climate areas have a higher chance of encountering a dangerous spider, as most larger species live in tropical and sub-tropical areas.
A spider most commonly seen in a house is the aptly named a house spider. Thin cobwebs that you see in the corners near ceilings are probably the work of common house spiders. A small and carefully controlled population of house spiders can actually be beneficial for a suburban or countryside home, as spiders will greatly decrease the number of flying insects. House spider bites are rare and harmless.
Jumping spiders are hunting spiders that occasionally seek refuge from cold weather in homes. This spider may bite if provoked, but such bites are only dangerous to their prey – smaller insects.
The long-legged cellar spider, more commonly known as daddy long-legs, is probably one of the most ubiquitous temperate-climate spiders. Contrary to the popular belief, these species are completely harmless.
The three species to watch out for are the hobo spider, the brown recluse, and the infamous black widow. The presence of any of these in the household warrants an immediate call for professional pest control.
The hobo spider is known to occasionally hide in hollow objects like shoes, and can bite if it feels threatened.
The brown recluse can spend daytime hours hiding in the folds of blankets or clothing. It is usually carried into the house while hiding in boxes.
Black widows usually hide in woodpiles and other small crevices. Luckily they are easily identified by their coloration and markings.
How to deal with spider infestation?
Other than the services of spider exterminators, there are several simple measures that can be taken to at least bring the problem down to a manageable level. However, if the spiders in question are a poisonous species and can pose danger to humans, or if the colonies are getting too large to handle, a professional spider exterminator should be contacted as soon as possible.
The most basic anti-spider measures are as follows:
- Regular thorough vacuuming. Floors and furnishings are the bare minimum. For a better effect, vacuum all the spaces behind and under the furniture, as well as all corners. Mopping ceilings and walls will also help. The main purpose of this is to remove any of the more apparent webs and possible nests.
- Boric acid powder, sprinkled near the likely nesting places and entry points is a reasonably effective and mostly safe way to kill any adult spiders.
- Any small gaps or cracks in the walls, floorboards, furniture, etc. must be filled in to deprive spiders of nesting spots. Covering all air vents with fine mesh is also a must.
- Make sure that objects like toys, clothing, shoes, or books don’t lie in disorderly piles. Be sure to take apart any pileups of objects both in the house and yard.
- Any rarely used objects should be tightly sealed or kept in tightly sealed plastic containers.
- Chemical spider repellants and poisons, especially ones of the over-the-counter kind, should be used with great caution. Excessive or reckless use may lead to harmful side effects for you, your family and pets.
- Glue-traps are useful when there are only a few spiders in the house. They are also considerably safer than repellant sprays.
- Ultrasonic pest repellers may prove effective against spiders, although if you or your neighbors keep pets, you will first have to make sure that the device does not bother them.