Spider behaviour
Some species of spiders appear only in summer, while others take refuge in our homes and are active almost all year long.
They are fond of insects of all kinds and prey on them in all sorts of places: in gardens, near bodies of water, in woodlands, etc.
Are spiders useful or bothersome?
Useful
- Because they eat such large quantities of insects, spiders help limit the destructive harm done by nuisance insects such as caterpillars, plant bugs and aphids in both natural and agricultural ecosystems.
- Inside homes, especially in basements, spiders also help get rid of unwanted guests like earwigs, ants, etc. Indeed, Health Canada recommends tolerating their presence.
Bothersome
- Spider webs are associated with neglect, uncleanliness and moisture, which are all conditions that attract the insects spiders feed on.
- Some people fear spiders to such an extent that they suffer from arachnophobia.
Are spiders dangerous to human beings?
The Montreal Insectarium has studied the issue extensively. Some highlights of their findings:
Spiders don’t sting, because they have no stingers.
Spiders tend to flee danger. But they can bite, using their chelicerae, the appendages resembling fangs that they normally use to pierce their prey. The fangs of house spiders are often too small to pierce human skin. If it happen, for example, you pinch a spider; the pain will generally be temporary.
Almost all spiders secrete venom, which paralyzes their prey. However, only about 30 of the 40,000 species of spiders worldwide produce venom that is dangerous to human health. None of those species is found in Quebec.
Spiders do not transmit disease. Some people develop allergic reactions when they come into contact with spiders, but such reactions have nothing to do with the spiders’ venom.
In short, we can state that Quebec spiders generally pose no danger to humans.
Tips for keeping spiders away from your home
Remember that a clean house attracts fewer nuisance insects, which means a more limited menu for spiders! Here are some other tips for keeping them away:
Deal with any moisture problems in the basement, and use a dehumidifier if necessary.
Sweep or vacuum often.
Make sure the house is airtight, especially around doors and windows.
Inspect items that have been left outside before bringing them into the house so as not to bring more insects inside.
Remove clutter from around the outside walls of the house. Don’t leave items lying on the ground; they can trap moisture, which attracts wood lice, earwigs, etc. (a veritable buffet for spiders).
Limit outdoor lighting, or connect lamps to motion detectors.
How to get rid of spiders?
Here are some tips for getting rid of spiders:
Remove spider webs inside the house every day. Their owners will no longer be able to capture prey and will move out.
If you see a spider near a door or window, use a soft brush to chase it outside.
Use a pesticide in case of a large infestation, indoors or outdoors. Products approved for use against spiders are easy to find at hardware stores and garden centres. Good to know: Certain repellents can be applied to the outer surfaces of doors and windows to prevent spiders from entering the house. Some spiders hunt without webs. That's why removing webs will not keep all visitors away.
Call a pest management specialist (exterminator) if you’re not able to get rid of undesirable creatures or if others return repeatedly.
To learn more about spiders
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