Spiders end up in swimming pools more often than most people expect. They don’t go in deliberately. Most fall in while hunting or wandering at night, then can’t climb out because pool walls are too slick. Depending on the species, a spider trapped in your pool can survive anywhere from 30 minutes to many hours underwater, so finding one that’s still alive is common.
Why Spiders End Up in Pools
Pools attract insects, and insects attract spiders. Outdoor lights near the water draw moths and beetles at night, which draws hunting spiders to the pool edge. From there, it’s easy to slip in. Some spiders, particularly ground-dwelling species, wander across yards at night looking for mates and stumble into the water by accident. Male Sydney funnel-web spiders in Australia are especially notorious for this, regularly turning up in suburban pools during warm months.
Smooth tile and fiberglass pool walls are the real problem. A spider that falls into a pond can usually grab vegetation or rough edges to pull itself out. Pool walls offer no grip, so the spider circles the perimeter endlessly looking for an exit until it either drowns or gets pulled into the skimmer.
Common Spiders Found in Pools
The species you’ll encounter depends on where you live, but a few types show up repeatedly.
Fishing spiders (Dolomedes) are the most water-adapted spiders you’re likely to see near a pool. Their bodies are covered in short, velvety, water-repelling hairs that let them stand and run on the water’s surface using surface tension, similar to water striders. Females can reach a leg span of about 80 mm (roughly 3 inches), which makes them startling to find skimming across your pool. If they dive underwater, air gets trapped against their body hairs and forms a thin silver film that functions like a personal oxygen supply. Their book lungs (breathing organs on the underside of the abdomen) open directly into this air layer, letting them breathe while submerged. They’re also extremely buoyant. If they let go of whatever they’re clinging to underwater, they pop right back to the surface completely dry.
Wolf spiders are fast, ground-hunting spiders that frequently wander into pools at night. They’re not water-adapted like fishing spiders but can float for a while before drowning.
Sydney funnel-web spiders are the most dangerous pool spider, found in eastern Australia. Males wander into backyards and fall into pools, where they can survive many hours submerged. Their venom contains a neurotoxin that attacks the human nervous system and can be fatal without treatment, though no deaths have occurred since antivenom became available. A funnel-web spider pulled from a pool may look dead but could still be alive and capable of biting.
How Long Spiders Survive Underwater
The answer varies dramatically by species. Researchers at Binghamton University documented a tropical spider, Trechalea extensa, surviving about 30 minutes fully submerged by maintaining an air film across its entire body. That’s a species with no special aquatic adaptations, just the standard water-repelling hairs most spiders have.
Species better adapted to water last far longer. Fishing spiders can stay submerged as long as they can hold onto something below the surface. Funnel-web spiders survive many hours in pool water. The takeaway: never assume a motionless spider in your pool is dead. Spiders enter a low-energy state underwater that conserves oxygen, and they can revive quickly once they reach air.
How to Remove a Spider From Your Pool
Use a long-handled pool skimmer net or a bucket on a pole. Scoop the spider from a distance and deposit it well away from the pool edge, in a garden bed or wooded area. Don’t use your hands, even with a spider that looks lifeless. A submerged spider that appears dead can start moving within minutes of being out of the water.
If you live in an area with medically significant spiders (funnel-webs in Australia, or brown recluses and black widows in parts of North America), take extra caution. Use a container with a lid if you want to identify the spider, and keep children and pets away from it. Killing a spider in the pool with chemicals isn’t practical since pool chlorine at normal levels doesn’t kill spiders quickly.
Keeping Spiders Out of Your Pool
You can’t eliminate the problem entirely, but several strategies reduce how often it happens.
- Move outdoor lighting away from the pool. Lights attract flying insects, which attract spiders. Positioning lights 10 to 15 feet from the water’s edge pulls the insect activity away from the pool.
- Trim vegetation near the pool. Bushes, ground cover, and woodpiles within a few feet of the pool give spiders a launching point. Clear a buffer zone of bare concrete or pavers around the deck.
- Install an animal escape ramp. Devices like the FrogLog provide a floating platform at the pool’s edge with a mesh ramp that lets trapped animals climb out over the coping. The animal bumps into it while circling the wall, climbs onto the platform, walks up the ramp, and exits. These work for spiders, frogs, lizards, and small mammals.
- Turn off the pump at night. Pool pumps running overnight pull floating animals into the skimmer before they can find an exit. Shutting the pump off at dusk, when most creatures become active, gives them a better chance of reaching an escape ramp or the pool steps. If local regulations require the pump to run continuously, even a brief shutdown window at dusk helps.
- Use a pool cover. A solid or mesh cover is the most effective barrier. Escape ramps can be placed on top of or underneath solar covers for pools that use them.
What to Do if You’re Bitten
Most pool spiders are harmless. A bite from a common wolf spider or fishing spider produces temporary pain and minor swelling, similar to a bee sting. Clean the bite with mild soap and water, apply antibiotic ointment, and hold a cool, damp cloth over it for 15 minutes each hour to bring down swelling. Over-the-counter pain relievers and antihistamines can help with discomfort and itching.
Watch the bite over the following days for signs of worsening: expanding redness, increasing pain, warmth, pus, or red streaks spreading from the site. These suggest infection and need medical attention.
For bites from funnel-web spiders, the situation is more urgent. Apply a pressure bandage over the bite and wrap the entire limb (the same technique used for snake bites in Australia), keep the person still, and get to a hospital for antivenom. Funnel-web envenomation can escalate quickly, but outcomes are excellent with prompt treatment.