Cave crickets, also called camel crickets or spider crickets, are one of the most common basement invaders in the U.S. They’re drawn to cool, damp, dark spaces, which means your basement, crawl space, or garage is essentially a five-star hotel for them. They don’t chirp like field crickets, they don’t bite, and they pose no real health risk. But they can show up in startling numbers, and their habit of leaping directly at you when startled makes them one of the more unsettling pests to find in your home.
What Cave Crickets Look Like
Cave crickets are tan to dark brown, humpbacked, and wingless. Their long, arching legs give them a spider-like appearance, which is why many people call them spider crickets. Adults range from about half an inch to an inch and a half in body length, but their oversized antennae and legs make them look much larger. Unlike the common house cricket, they have no wings and produce no sound. If you’re finding silent, jumping, spider-shaped insects in your basement, you’re almost certainly looking at cave crickets.
Why They Jump at You
Cave crickets have poor eyesight. When they sense a large shape nearby, they can’t tell whether it’s a predator or a wall. Their only defense is to leap toward the perceived threat, hoping to startle it into backing off. It’s a blind defensive reflex, not aggression. They aren’t trying to land on you. They simply can’t tell the difference between you and a rock.
Why Your Basement Attracts Them
Moisture is the single biggest factor. Cave crickets need humid environments to survive, and basements hold more humidity than any other part of a typical home. They gravitate toward the dampest corners: near floor drains, water heaters, sump pumps, and anywhere condensation collects. An unfinished or poorly ventilated basement is a natural fit for them.
Beyond moisture, they’re looking for darkness and food. Outdoors, cave crickets live under logs and stones, feeding on decaying plant material. Inside your home, they’ll eat almost anything organic: cardboard, fabric, dead insects, even biological material building up in wall cavities or crawl spaces. The odor of dead insects or decaying organic matter in a wall void can actively pull them toward your house from the yard.
They enter through basement-level openings. Gaps around pipes, cracks in the foundation, poorly sealed basement windows, spaces under doors, and openings where utility lines pass through walls are all common entry points. Because they’re flat-bodied and flexible, they can squeeze through surprisingly small gaps.
Are They Harmful?
Cave crickets are classified as nuisance pests. They don’t bite humans, they aren’t known to carry diseases, and they don’t produce the irritating chirping sound that field crickets do. For most people, the problem is simply that they’re unsettling to encounter, especially in large numbers.
That said, they can cause minor property damage if an infestation goes unchecked. When cave crickets can’t find their preferred food sources, they’ll chew on stored items like garments, linens, and cardboard boxes packed away in a garage or basement. A telltale sign of a heavy infestation is the presence of dark fecal smears on surfaces like floor joists, basement walls, or storage boxes.
How to Get Rid of Them
Cut the Moisture
This is the most effective long-term fix. Reducing humidity removes the main reason cave crickets stay in your home. A dehumidifier in the basement, set to keep relative humidity below 60%, makes the space far less hospitable. Improving ventilation helps too: opening vents in crawl spaces, running exhaust fans, or adding airflow to stagnant corners. Fix any leaking pipes, dripping faucets, or condensation issues around water heaters. If the dampness goes away, the crickets typically follow.
Seal Entry Points
Walk the perimeter of your basement and crawl space looking for gaps. Focus on where pipes and wires enter the foundation, cracks in concrete walls or floors, gaps around basement windows, and the space beneath exterior doors. Silicone caulk works for small cracks. Expanding foam fills larger gaps around pipes. Door sweeps and weatherstripping close off the space under doors. The goal isn’t perfection; even reducing the number of entry points significantly cuts down on new crickets coming in.
Use Sticky Traps
Sticky traps (glue boards) are the simplest and most effective physical control method. Place them flat against walls in the dampest, darkest corners of your basement, near floor drains, along the base of foundation walls, and in crawl spaces. Cave crickets travel along edges and walls, so traps placed in the middle of a room won’t catch much. Check and replace traps every week or two. They also serve as a monitoring tool: if your traps are filling up quickly, you know the population is still high and you need to address the underlying moisture or entry-point issues.
Try Diatomaceous Earth
Food-grade diatomaceous earth is a fine powder made from fossilized algae with microscopic, abrasive edges. When cave crickets walk through it, the tiny particles work their way into their leg joints and scrape off the waxy protective layer on their exoskeletons, causing them to dehydrate and die. Spread a light dusting in areas where crickets congregate: along basement walls, behind water heaters, around the edges of crawl spaces, and near known entry points. It’s nontoxic to humans and pets, but it works slowly and needs to stay dry to remain effective. Reapply after any moisture exposure.
Remove Outdoor Habitat
Cave crickets living right next to your foundation are the ones most likely to find their way inside. Clear away leaf litter, mulch, stacked firewood, stones, and debris from the perimeter of your home, especially near basement windows and ground-level vents. Moving these harborage sites even a few feet from the foundation reduces the number of crickets close enough to wander in. Keeping outdoor lights off or switching to yellow bulbs also helps, since bright lights attract the insects that cave crickets feed on.
Signs of a Larger Infestation
Seeing one or two cave crickets in a basement during late summer or fall is normal, especially after heavy rain. But if you’re regularly finding five or more at a time, noticing dark fecal streaks on floor joists or walls, or discovering chewed fabric or cardboard in storage areas, the population has likely established itself indoors. At that point, combining multiple approaches (dehumidification, sealing, traps, and diatomaceous earth) gives you the best results. If the numbers don’t drop within a few weeks of consistent effort, a pest control professional can treat the crawl space and foundation perimeter more aggressively.
Cave crickets are seasonal visitors for many homeowners, showing up most often in late summer and early fall when outdoor conditions dry out and they go searching for moisture. Addressing the humidity and access points in your basement before that seasonal window is the most reliable way to keep them from becoming a recurring problem.