Spiders
Why Are They a Problem?
Spiders are actually beneficial because they eat insects. They frequently stray into houses and may be accidentally introduced on firewood, on laundry that was hung out to dry, and on flowers. The webs may be a nuisance in storage areas and in garages.
Spider Biology
Spiders are not insects, but arachnids — they have eight legs while insects have six. Spiders kill their prey with a poisonous bite: very few are dangerous to humans. A spider web has two parts: non-sticky scaffolding that the spider walks on and a sticky spiral of threads that catches insects. When a web is built the spider hides on the edge of the web and waits until a victim gets caught on the sticky threads. When it feels the vibrations of the prey trying to escape, the spider rushes out and secures the victim with silk, injects it with paralyzing venom, which liquefies it. Next the spider “drinks” the contents of the prey and discards the dried-out shell.
The wolf spider does not build a web — it hunts for prey. The black widow spider has a bite that can be dangerous to humans, but can be treated with antivenom. A red hourglass shape on the underside of its abdomen distinguishes the black widow from other spiders. Certain species can range into southern parts of Canada. The black widow weaves a small web close to the ground and will normally be found in crawl spaces or garages rather than in the house.
How to Prevent Invasions & Infestations
- Keeping your house clean reduces the number of pests that are food sources for spiders.
- Sealing cracks and openings around the ground level of the structure may keep spiders from entering the building.
- Reduce humidity as much as possible because spiders prefer humid environments.
- Wear gloves when handling stored items in dark damp places to avoid bites.
- Use motion sensor outdoor lighting — this may reduce the number of webs around outdoor lights because the lights won’t be on all the time.
Recommended Treatment
If you have tried preventative methods and really cannot live with spiders, you may wish to use an insect control product. Use the recommended product around baseboards, in cracks and crevices in walls, behind and beneath cabinets, refrigerators and around window frames. Raid® Spider Blaster Bug Killer kills spiders on contact and will provide residual killing for up to 2 weeks.