If you've got a dock on Lake Coeur d'Alene or Hayden Lake, you know the drill: you clear the webs one weekend, and by the next they're back thicker than ever — strung across the railings, the boat lift, and the underside of the decking. Dock spiders are relentless on the water, but you can absolutely keep them in check. Here's what actually works.
Why docks are spider magnets
Open water produces enormous numbers of midges, mayflies, and other insects, and they swarm toward any light at night. Spiders simply follow the buffet — and your dock, with its railings, pilings, lift, and shaded underside, is prime real estate right in the middle of it. That's why docks web up so much faster than the rest of the property.
What actually keeps them away
Spraying alone doesn't cut it on a dock — and dumping chemicals near the water isn't okay anyway. The approach that works has two parts: physically remove the webs and egg sacs, then apply a water-safe repellent so spiders don't want to rebuild there. Clearing egg sacs is key, because every one you leave is the next wave of spiders. That's exactly how our dock spider treatments work.
DIY steps that genuinely help
- Knock down and vacuum webs and egg sacs regularly — consistency beats intensity.
- Cut back dock lighting at night, or switch to yellow bulbs, so you're not drawing clouds of insects (and the spiders that eat them).
- Clear clutter from under and around the dock and boat lift so there are fewer sheltered anchor points.
- Wipe down the boat lift, pilings, and railing undersides where webs concentrate.
Why “water-safe” isn't optional
Anything you apply on a dock can end up in the lake, so it has to be a product labeled for use above and near water — never a generic yard spray. Protecting your shoreline, your pets, and everyone who swims off the dock matters as much as getting rid of the spiders. We only use water-appropriate products, and we never spray into the water.
Keeping it gone all summer
Because spiders re-colonize fast over open water, the only thing that truly holds them back is staying on top of it through the warm months. Most lake and river properties keep their docks clear with recurring visits from spring through early fall. Want your dock back? See our dock spider treatment page, or call or text (208) 405-0004.
Frequently asked questions
What are the big spiders all over my dock?
Most are harmless web-builders — often called dock spiders — along with orb-weavers, drawn to the heavy insect activity over the water. They're a nuisance more than a danger, but the webs and egg sacs build up fast if you don't stay ahead of them.
Is it safe to spray for spiders near the lake?
Only with products specifically labeled for use above and near water. Generic yard sprays don't belong near a lake or river. Our dock treatments use water-safe repellents, and we never spray into the water.
How often should I treat my dock for spiders?
Because spiders rebuild quickly over open water, most lake properties stay ahead of them with recurring treatments through the warm months rather than a single visit. We'll recommend a rhythm based on how heavy your dock's pressure is.