California is home to at least seven common cricket species, ranging from the familiar chirping field cricket to the large, alien-looking Jerusalem cricket that startles homeowners when it turns up under a rock or in a garden bed. Some are native, some are introduced, and they occupy surprisingly different niches across the state’s varied landscapes.
Common Cricket Species in California
The crickets you’re most likely to encounter in California fall into a few distinct groups. Field crickets are the classic dark brown or black crickets that chirp from lawns and gardens on warm nights. House crickets are their lighter, yellowish-brown cousins that tend to move indoors, especially as temperatures drop. Both are widespread across the state and are the species most people picture when they hear the word “cricket.”
Beyond those familiar types, California hosts several more unusual species. Jerusalem crickets (and their close relative, the dark Jerusalem cricket) are large, wingless, soil-dwelling insects found primarily in the western and central parts of the state. Snowy tree crickets are pale green, delicate insects that live in shrubs and trees and are sometimes called “thermometer crickets” because their chirp rate changes predictably with temperature. Square-legged camel crickets are humpbacked, silent species that favor dark, damp spaces like basements, crawl spaces, and caves. Mormon crickets, despite their name, are actually large katydids that occasionally swarm in northern California and the Great Basin region.
Jerusalem Crickets: California’s Most Misunderstood Insect
Jerusalem crickets generate more alarmed internet searches than any other cricket in the state. They’re big, sometimes over two inches long, with a round, bald head that looks almost human, a striped amber-and-brown abdomen, and thick, powerful legs built for digging. They spend most of their lives underground, tunneling through soil and feeding on decaying plant material and roots. You’ll typically find them after turning over a stone, pulling up landscape fabric, or digging in a garden bed.
Despite their intimidating appearance, Jerusalem crickets are not venomous. They can bite if you pick one up or handle it roughly, and those strong jaws can produce moderate, short-lived pain, but there’s no venom or toxin involved. The bite is purely mechanical. They have no interest in seeking out humans and will try to retreat into the soil if disturbed. If you find one in your yard, it’s actually a sign of healthy, well-aerated soil. These crickets are beneficial decomposers that break down organic matter and create channels for water and roots.
Field Crickets and Garden Damage
Field crickets are the species most likely to cause noticeable damage in California gardens and agricultural fields. They feed at night, hiding during the day under debris, mulch, or in soil cracks. Their feeding pattern involves gouging and girdling the stems of young plants, and they may also chew on leaves. According to the UC Statewide Integrated Pest Management Program, this damage is significant only in occasional seasons and is most common in California’s low desert regions, where large populations can build up under the right conditions.
For home gardeners, field crickets are rarely a serious threat. A few crickets in a yard are part of the normal ecosystem, eating decaying plant material and serving as food for birds, lizards, and spiders. Problems tend to arise only when populations spike, usually after a wet spring that produces abundant plant growth followed by drying conditions that concentrate crickets around irrigated gardens. Reducing ground-level hiding spots like boards, thick mulch layers, and piled debris is the simplest way to discourage large numbers near your home.
House Crickets and Indoor Infestations
House crickets are the ones that keep you awake with chirping from somewhere behind the refrigerator. They’re an introduced species, originally from southwestern Asia, and they thrive in California’s warmer inland valleys and southern regions. Males chirp to attract mates, and they do it most persistently at night in warm conditions.
Indoors, house crickets seek out warmth and moisture. They can feed on a remarkably wide range of materials: crumbs, pet food, fabric, paper, and even the glue in book bindings. A small number are more of an annoyance than a problem, but a sustained population can damage clothing and fabrics, particularly items made of cotton, silk, or wool. Sealing gaps around doors, windows, and utility pipes is the most effective prevention. They’re drawn to outdoor lighting at night, so switching to yellow or sodium vapor bulbs near entry points reduces the number that gather near your home.
Crickets by Region
California’s geographic diversity means different areas host different cricket communities. In the coastal regions from San Francisco south through Los Angeles and San Diego, Jerusalem crickets and field crickets are the most common ground-dwelling species. The Central Valley, with its agricultural land and warm summers, supports large field cricket populations that occasionally affect crops like cotton and young vegetable seedlings. Desert regions in the southeast, including the Imperial and Coachella valleys, see the most concentrated agricultural damage from field crickets during boom years.
Northern California and the Sierra Nevada foothills are where you’re more likely to encounter Mormon crickets during periodic population surges, though these events are irregular and localized. Camel crickets turn up statewide wherever there are cool, damp enclosed spaces, but they’re particularly common in older homes with unfinished basements or crawl spaces in the Bay Area and northern coastal regions where humidity stays high year-round.
Why Crickets Chirp (and How to Stop It)
Only male crickets chirp, and they do it by rubbing a scraper on one wing against a series of ridges on the other. The chirping serves two purposes: attracting females and warning rival males to stay away. Temperature directly controls the rate. Warmer air means faster chirping. The snowy tree cricket is so predictable in this regard that you can estimate the temperature in Fahrenheit by counting the number of chirps in 13 seconds and adding 40.
If indoor chirping is driving you up the wall, the cricket is almost certainly a male house cricket or field cricket that wandered in. They tend to hide in warm spots near appliances, along baseboards, or in closets. Sticky traps placed along walls in the room where you hear chirping will usually catch the culprit within a night or two. A single cricket can sound like it’s everywhere because the sound reflects off walls, making it hard to pinpoint, but patience and a few well-placed traps solve the problem without chemicals.