House Crickets: The Chirping Isn't the Only Thing to Watch For

A steady chirping sound coming from somewhere unseen after dark is usually the first, and sometimes only, sign that a house cricket has moved in. House crickets are light yellowish-brown insects, typically 19 to 22 millimetres long, with three dark bands visible across the head, and they belong to Gryllidae, the cricket family best known for exactly this sound. What most people don't realise is that the chirping is tied to a genuinely interesting piece of science, and that the sound itself usually isn't the part of a cricket problem actually worth worrying about.

The chirp, and the law that can estimate temperature from it

Only adult male crickets chirp, and they do it by rubbing their wings together — one wing functions as a comb, the other as a file — to produce one of three distinct songs used for calling a mate, courtship, or aggression toward rival males. The detail that makes this more than just background noise: chirping frequency is directly tied to ambient temperature. This relationship is well-established enough to have its own name, Dolbear's Law, which describes how counting a cricket's chirps over a set interval can be used to estimate the surrounding temperature fairly accurately — a rare case of an everyday nuisance sound doubling as a legitimate piece of applied entomology.

An insect that hears through its legs

Crickets don't have ears in any conventional sense. Their auditory organs are located on their lower forelegs rather than on the head, which is how they're able to detect the chirping of other crickets, including rivals and potential mates, despite having no visible ear structure at all.

Why warmth and light pull them indoors in the first place

House crickets are cold-blooded, so their activity level and metabolism rise directly with temperature, making warmth a strong pull toward a heated indoor space, especially as outdoor temperatures drop. They're also drawn to light, and are nocturnal by nature — spending daylight hours tucked into cracks, cluttered areas, and dark corners, then emerging at night to feed and chirp. That combination of behaviours is exactly why a cricket is often heard for days before it's ever actually seen.

The fabric damage that often gets missed

This is the part of a house cricket problem that's easy to underestimate. House crickets are omnivorous scavengers that, in the wild, feed on rotting leaves, fruit, and other insects — and indoors, that diet readily extends to fabric. Wool, cotton, silk, and synthetic materials are all documented food sources for house crickets, with clothing soiled by perspiration being particularly attractive to them. They typically surface-feed, pulling fibres loose and leaving the fabric visibly roughened, and in a heavier infestation, large sections of fabric can be eaten through entirely. Indoors, their scavenging has also been documented extending to things like wallpaper glue — a reminder that a cricket population isn't purely a noise issue.

• Reduce exterior lighting near entry points at night, since both light and warmth are two of the strongest draws bringing crickets indoors.
• Seal obvious gaps around doors, windows, and foundation cracks to reduce how easily they wander in.
• Store fabric properly and launder sweat-soiled clothing promptly rather than leaving it in a pile, since it's specifically more attractive to house crickets.
• Reduce clutter in storage areas, closets, and basements — the dark, undisturbed spots crickets favour for hiding during the day.
• If chirping persists for more than a few nights or fabric shows unexplained roughening or holes, treat that as a sign of an actual population rather than one stray cricket, and worth a professional look.

A single cricket chirping for a night or two usually isn't cause for concern, but a persistent, ongoing sound — or any sign of damage to stored fabric — is worth taking seriously. A free Sevacorp inspection can confirm what's actually present and where it's likely hiding during the day.

• Sources:
• University of Maryland Extension — "Crickets" — https://extension.umd.edu/resource/crickets
• National Pest Management Association (PestWorld) — "House Cricket Information" — https://www.pestworld.org/pest-guide/occasional-invaders/house-crickets/
• University of Missouri Extension — Household and Structural Pests publication G7366 — https://extension.missouri.edu/publications/g7366