Spider Killer Sprays

Many give knockdown on the spiders they contact. Some also leave a residual deposit on treated surfaces that helps reduce repeat activity on those surfaces over time. Check the label for which you are buying and where it can be applied.

Worth asking first. A glass and a piece of card will move most house spiders outside in a few seconds, and released well away from the wall they rarely walk straight back in - that is what our guide to keeping spiders out of your home recommends starting with. A spray earns its place where you want to treat entry points and resting spots rather than deal with individual spiders, or where numbers are persistent enough that catching them one at a time is not practical.

At the places spiders enter and rest: window and door frames, thresholds, air brick surrounds, where pipes enter walls, ceiling corners, and behind furniture in cellars, lofts and garages. Treat edges and entry points rather than open floor.

Follow the label on the individual product. Keep children and pets out until treated surfaces are completely dry, ventilate as directed, and do not treat food preparation surfaces or anything a pet may lick or chew.

Follow the reapplication interval on the label. In general, re-treat after cleaning or anything else that removes the deposit, and again if activity returns.

Do not rely on it. A single sac can hold up to a few hundred eggs and they usually hatch within two to three weeks, and the silk is a reasonable barrier. Vacuum the sac up along with the web instead, then empty the vacuum straight into an outside bin rather than leaving the bag or canister indoors. Check the places sacs get missed: ceiling corners, behind and under furniture, inside window reveals, and undisturbed corners of lofts, cellars and garages.

Two different pictures. In autumn, mature males wander in looking for females, so new spiders keep arriving no matter how recently you treated - that is seasonal and it settles. Year-round, spiders return because there is prey and a way in, so reducing flies and other insects indoors, and sealing gaps around frames and air bricks, does more than repeat spraying.

Seal gaps around window and door frames, air bricks, vents and pipe entries, and fit brush strips to door bottoms - our insect proofing range covers the fittings. Clear webs as you find them and cut back planting touching the walls.

Almost certainly not. Very few UK spiders can bite through human skin, and none is medically dangerous in the way people often fear. The false widow occasionally bites, usually with no more than local pain and swelling, and anyone with an unusual reaction should see a doctor. Most spider control is about nuisance rather than risk, which is worth knowing before reaching for a spray.

Rarely necessary for spiders. Consider it if activity is heavy and persistent year-round in a commercial or food setting, if you cannot find or reach where they are getting in, or if someone has had an unusual reaction to a bite. Look for a qualified pest controller with BPCA membership.