Crickets in Your Basement This Fall? Why They're There and How to Get Them Out

Quick answer: Crickets appear in Ontario basements in September and October because the nights get cold and your basement is warm, dark and damp — three things a cricket is built to look for. They come in at ground level through window wells, door sweeps, dryer vents and foundation cracks. Sticky monitors and a dehumidifier handle the ones already inside; sealing the ground-level gaps is what stops the next wave. And here is the part most homeowners miss: whatever route the crickets took is the same route mice will use four weeks later.

Which cricket do you actually have?

Three kinds turn up in Ontario homes, and they behave differently enough that it is worth thirty seconds to tell them apart.

Field crickets are the classic ones — glossy black or very dark brown, roughly 15–25 mm, with long antennae and obvious jumping legs. They live outdoors in lawns, mulch beds and under stones, and they push indoors in numbers when the first cold nights arrive. Males chirp. These are what most Ontario homeowners are dealing with in September.

House crickets are lighter — yellowish-brown with darker bands across the head. Less common in Ontario homes, but they establish indoors more readily, and they are the ones still chirping in your utility room in January.

Camel crickets — also called spider or cave crickets — look wrong the first time you see one. Humpbacked, tan and mottled, wingless, enormous back legs, very long antennae. They do not chirp, because they have no sound-producing wings. They jump toward you when startled, which is a defensive reflex and the reason people find them far more alarming than they need to be. Harmless, but a strong moisture indicator: camel crickets mean that space is damper than it should be.

University of Minnesota Extension’s overview of crickets as household nuisance insects and UC IPM’s cricket management notes both land on the same conclusion we do: these are accidental invaders. They are not breeding through your house the way a cockroach would.

Why basements, and why right now

The trigger is temperature differential. Field crickets are outdoor insects with no cold tolerance to speak of. When overnight lows drop into single digits — which in Barrie, Innisfil and Orillia happens well before it does downtown — they move toward warmth, and warmth at ground level means your foundation.

Then three conditions decide whether they stay.

Moisture. Crickets lose water quickly and need humidity to survive. A basement running above roughly 60% relative humidity is comfortable for them; one at 45% is not. This single variable does more work than any product you can buy.

Darkness and clutter. Cardboard boxes on a concrete floor, stacked lumber, storage against the foundation wall, a crawl space — all of it is cover. Crickets hide by day and move at night.

Food. They are omnivorous scavengers. Cardboard, paper, fabric, pet food, organic debris in a floor drain, and dead insects on a windowsill all qualify. A finished basement with a laundry room and a bag of dog food supports them indefinitely.

Cottage properties and rural homes get hit hardest, because there is more habitat right against the foundation and often a crawl space or unfinished lower level with an earth or gravel floor. This is a routine September call for us in Innisfil and through Muskoka, where a shoulder-season cottage sits closed and unheated and becomes exactly the shelter a cricket is looking for.

The chirp problem

A single male field cricket in a wall cavity or under a basement stair can make a room genuinely unusable at night. The chirp is 4–5 kHz, which is close to the frequency range human hearing is most sensitive to, and it is deliberately hard to localize — the sound reflects off concrete and the cricket stops the moment you get close.

Two practical tactics. First, the chirping is temperature-dependent: it slows noticeably in a cold room and often stops below about 13°C, so dropping the temperature in an unfinished space overnight can buy you sleep while you deal with the source. Second, they chirp less when disturbed, so pinning the location usually means sitting still in the dark for several minutes rather than walking around with a flashlight.

Camel crickets, for the record, are silent. If you have noise, you have field or house crickets.

What actually works

Drop the humidity. A dehumidifier set to 45–50% in the basement is the highest-leverage thing on this list. It makes the space inhospitable rather than merely reducing the count, and it also discourages the whole moisture-loving group — centipedes and springtails show up in exactly the same conditions and often in the same week.

Put down sticky monitors. Flat glue boards along the base of the foundation wall, behind the furnace, at the bottom of the stairs and in the corners. They physically remove crickets and, more usefully, they tell you where the traffic is concentrated — which points at the entry.

Seal ground level. Door sweeps on the basement and garage doors. Window well covers, and wells cleared of leaf litter. Caulk on foundation cracks and around the rim joist. Screens on dryer and bath vents. Weatherstrip the man-door from an attached garage. Nothing here is exotic; it is a Saturday and about $60 in materials, and it is the only step that reduces next year’s count.

Clear the perimeter. Pull mulch, leaf piles, firewood and long grass back from the foundation by half a metre. Cricket habitat within touching distance of the wall means crickets against the wall when the temperature drops.

Change the outdoor lighting. White porch and garage lights pull in crickets and everything else at night. Warm-toned or amber bulbs attract dramatically fewer insects, and moving the light away from the door helps more than changing the bulb.

What does not work

Ultrasonic plug-in devices do nothing for crickets. Grocery-store foggers kill what they contact in open air and leave everything sheltered in the cracks, which is where crickets are. Scattering loose insecticide dust across a basement floor is worse than useless in a home with pets or children. And spraying the interior perimeter without dealing with the moisture and the gaps buys you a few days, then the count returns — because the source is outside.

The part worth paying attention to

Crickets are not a serious pest. They do not bite, they carry no meaningful disease risk, and other than occasional damage to fabric or paper they cause no harm. If that were the end of it, this would be a nuisance article.

It is not the end of it. Crickets are a diagnostic. A cricket in your basement is physical proof of two things: there is a ground-level opening into your foundation, and the space behind it holds enough humidity to sustain an insect that dies quickly in dry air.

Both of those facts matter far more in October than they do in September. The gap a field cricket walks through is generally larger than the 6 mm a house mouse needs, and the same cold snap that pushed the crickets in is what puts mice against your foundation a few weeks later. Every autumn we take calls from homeowners who saw crickets in early September, dealt with them, and called back in mid-October about scratching in the ceiling. Our library page on the house mouse covers what that escalation looks like.

The efficient move is to treat the cricket appearance as the free warning it is and close the building envelope once, for both.

How we approach it

Any job starts with a $95 professional inspection, credited in full when you book the treatment. On a cricket call that means a moisture reading in the basement, a ground-level entry survey around the whole foundation, and a monitor placement plan — plus an honest answer about whether you need a treatment at all. Sometimes a dehumidifier and three door sweeps is the entire fix, and we would rather tell you that than sell you a service.

When treatment is warranted, General Insect Control starts at $395 for exterior or $475 for interior and exterior, using reduced-risk products, applied by technicians who are employed by us — licensed, background-checked, never subcontracted. Sani IQ is licensed under the Ontario Pesticides Act, registered with the MECP, BBB Accredited, carries $5M liability insurance and holds a 5.0 Google rating. One-time services carry a 60-day guarantee.

But a one-time treatment is the entry point, not the answer. Crickets are a seasonal event with a seasonal cause, and so are the boxelder bugs in October, the cluster flies at the first warm November afternoon, the ants in April and the wasps in July — all through the same envelope. Insect Control at $845 per year covers the exterior on a quarterly cycle so the pressure never builds; Essentials at $1,195 adds rodent coverage, which is the pairing that actually matches what a cricket is telling you about your foundation. See how our residential pest control programs are structured, or take the 60-second quote quiz for a real number without a phone call. If you would rather just talk to someone, we are at (705) 302-1887.

Frequently asked questions

Are crickets in the basement dangerous? No. They do not bite or sting and pose no meaningful health risk. Occasionally they chew fabric, paper or cardboard. The real concern is what their presence reveals about moisture and entry points.

Why do crickets jump at me? That is the camel cricket, and it is a startle response with no aim behind it — they jump toward movement because they cannot see well. Harmless, if unnerving.

Will crickets breed in my house? Field crickets generally will not; they are outdoor breeders that wander in and die off. House crickets can establish indoors if there is enough humidity and food, which is one more reason the dehumidifier matters.

How do I stop the chirping tonight? Lower the temperature in the space — chirping slows sharply in the cold and usually stops below about 13°C — and put glue boards along the wall base near where the sound seems loudest. Sitting still in the dark for a few minutes localizes it better than walking around.

Do ultrasonic repellers work on crickets? No. There is no credible evidence they control crickets or any other household insect. The money is better spent on a dehumidifier and door sweeps.

Should I be worried about mice too? Reasonably, yes. Crickets confirm you have ground-level openings and a humid lower level. Mice follow the same route within weeks as nights get colder, and a $95 inspection credited toward treatment is a cheap way to find out how exposed you are before that happens.