Cave crickets are opportunistic omnivores that eat just about anything organic they can find, from decaying leaves and fungi in the wild to cardboard, fabric, and crumbs inside your basement. These humpbacked, wingless insects belong to the family Rhaphidophoridae, and their flexible diet is a big part of why they thrive in dark, resource-scarce environments that would starve most other creatures. What they consume shifts dramatically depending on whether they are foraging outdoors at night, roosting in a natural cave by day, or taking up unwelcome residence in a human structure.
Nighttime Foraging Above Ground
Most cave crickets are not full-time cave dwellers. Species like Ceuthophilus secretus in central Texas spend their days roosting inside caves but emerge at dusk to forage on the surface. A mark-recapture study that tracked roughly 2,000 of these crickets found them wandering up to 105 meters from the cave entrance, with fairly even densities out to about 80 meters.1The American Midland Naturalist. Foraging Range and Habitat Use of Ceuthophilus secretus (Orthoptera: Rhaphidophoridae), a Key Trogloxene in Central Texas Cave Communities That is a surprisingly large foraging radius for an insect only a couple of centimeters long.
The same study recorded where the crickets turned up during their nightly outings: about 31% were found in grasses, 22% in leaf litter, and 20% on herbaceous vegetation, nearly all at ground level.2BioOne Complete (The American Midland Naturalist). Foraging Range and Habitat Use of Ceuthophilus secretus (Orthoptera: Rhaphidophoridae), a Key Trogloxene in Central Texas Cave Communities Out there they are eating whatever organic material is available: dead plant matter, fallen fruit, fungal growth on decaying wood, other small invertebrates (dead or alive), and animal droppings. They are not picky. A cave cricket’s mouthparts are generalized enough to chew soft plant tissue, scrape at mold, or gnaw on a dead insect with roughly equal ease. This generalist strategy means their exact diet depends on what the local habitat offers.
Why Caves Have Almost No Food
Underground environments are energy deserts. Without sunlight, there is no photosynthesis, which means no plants growing on cave walls and no base of the food chain the way there is outside. Cave-dwelling animals depend almost entirely on food that gets carried in from the surface, whether by flowing water, animal visitors, or gravity pulling debris through cracks. In smaller caves without large bat colonies, cave crickets become the primary delivery system for that outside energy.3Encyclopedia of Caves. Food sources
The cycle works like this: crickets forage outside at night, fill their guts with organic material, then return underground to roost. Inside the cave, they defecate, lay eggs, shed skin, and eventually die. Their guano, eggs, cast-off exoskeletons, and carcasses become the food supply for a whole community of smaller invertebrates that never leave the cave. Researchers describe cave crickets as keystone species in these ecosystems, supporting terrestrial communities of mites, beetles, springtails, and other tiny animals that specialize on cricket-derived material.3Encyclopedia of Caves. Food sources The crickets are, in effect, a nutrient pipeline connecting the sunlit surface world to the pitch-dark one below.
What They Eat Inside a Cave
While roosting underground during the day, cave crickets do not simply wait for nightfall. They also feed on whatever the cave environment provides, which is not much but is not nothing. Fungal growth on damp rock surfaces, bat guano in caves with bat populations, dead invertebrates, and each other’s shed skins all get consumed. In caves with large populations, crickets will eat their own kind’s eggs and newly hatched nymphs. This is not accidental. When food is scarce and the population is dense, cannibalism becomes a practical protein source.
Research on Mormon crickets, a related group of large orthopterans in western North America, has shown that cannibalism spikes specifically when insects are deprived of protein and salt. Providing those nutrients experimentally reduced cannibalistic attacks.4PubMed Central. Cannibal crickets on a forced march for protein and salt While that study focused on Mormon crickets rather than cave crickets, the nutritional logic applies broadly to omnivorous orthopterans: when the diet lacks protein, nearby members of your own species start looking like a viable meal. In cave systems where food input is low and cricket densities are high, the pressure to cannibalize is real.
How Gut Bacteria Expand Their Menu
A major reason cave crickets can survive on such low-quality food is that they do not digest it alone. Their guts are home to microbial communities that break down tough plant compounds the cricket’s own enzymes could not handle. This is a common strategy among detritivores: the animal eats the decaying material, and specialized bacteria inside the gut do the heavy biochemical lifting to extract usable nutrients from it.5Journal of Arid Environments. Nutrition and habitat selection in desert detritivores
A study on Diestrammena japanica, a cave cricket species in Asia, mapped the bacterial communities in cricket guts from different cave zones. Firmicutes bacteria dominated in all samples, and the most abundant single genus was Lactobacillus, making up between about 37% and 60% of gut bacteria depending on how deep inside the cave the crickets lived. Functional analysis predicted that roughly 35% of the gut bacteria were involved in nutritional functions for the host, including processing amino acids, carbohydrates, and inorganic ions.6Frontiers in Microbiology. Gut bacteria reflect the adaptation of Diestrammena japanica (Orthoptera: Rhaphidophoridae) to the cave In plain terms, the crickets carry an internal chemical factory staffed by bacteria that helps them wring nutrition out of food sources that would otherwise be indigestible.
Separately, researchers screening the greenhouse camel cricket (Diestrammena asynamora), a species commonly found in basements and greenhouses worldwide, discovered bacteria in its gut capable of growing on lignocellulosic compounds, the tough structural fibers in plant cell walls.7PubMed Central. Public questions spur the discovery of new bacterial species associated with lignin bioconversion of industrial waste This helps explain how cave crickets can get calories from materials that seem impossibly nutrient-poor, like rotting wood or damp cardboard. Their microbial partners unlock energy from the cellulose and lignin that most animals cannot touch.
What They Eat When They Move Into Your House
A basement, crawl space, or garage is basically a human-made cave from a cricket’s perspective: dark, cool, and humid. Cave crickets show up indoors because the conditions mimic what they seek in nature, and they stay because there is usually enough to eat. Indoors, their diet shifts to whatever organic material is lying around. Common targets include:
- Cardboard and paper: Stored boxes, old newspapers, and paper grocery bags are all fair game, especially if they are slightly damp. Moisture softens the cellulose and makes it easier for gut bacteria to break down.
- Fabric and clothing: Cotton, silk, wool, and linen stored in dark closets or laundry piles can sustain damage from cave crickets. Synthetic fibers hold less nutritional value, so they tend to be left alone unless blended with natural materials.
- Crumbs and food residue: Pet food left out overnight, grease spatters behind a stove, or forgotten pantry spills are an easy buffet.
- Fungi and mold: Damp basements often grow mold on walls, joists, or stored items. Cave crickets graze on this readily.
- Other insects: Dead spiders, flies, or even other crickets found in corners and window wells get scavenged. Live insects are sometimes taken too, especially if the prey is smaller or already injured.
The damage cave crickets cause indoors is usually minor compared to something like a termite infestation. You might notice small, irregular holes chewed in a stored garment or ragged edges on a cardboard box. Because they feed on surfaces rather than boring into structural wood, they do not threaten the integrity of your home. The bigger annoyance is their numbers: a single moist basement can harbor dozens or hundreds of them, and their habit of leaping unpredictably when startled tends to alarm people more than their actual feeding damage does.
Why Moisture Matters More Than Food
If you want to understand what draws cave crickets to a particular spot, humidity is the answer more often than food availability. These insects lose water through their exoskeletons at a rate that makes staying hydrated a constant challenge. Research on three species of Hadenoecus cave crickets in the eastern United States found that species spending more time deep inside caves had higher rates of water loss compared to those that ventured outside more regularly. The more cave-adapted the species, the more it depended on the water-saturated conditions underground to avoid drying out.8PubMed. Increased cave dwelling reduces the ability of cave crickets to resist dehydration
This explains a lot about their indoor behavior. Cave crickets cluster in the dampest parts of a house: near sump pumps, along basement walls with condensation, under leaky pipes, around laundry drains. A perfectly dry basement with food on every surface would attract fewer crickets than a wet basement with almost nothing to eat. If you are trying to discourage them, reducing indoor humidity with a dehumidifier is usually more effective than trying to eliminate every scrap of organic material they might consume.
The Global Spread of the Greenhouse Camel Cricket
Not every cave cricket you find indoors is a local species. The greenhouse camel cricket, Diestrammena asynamora (sometimes listed under its older name Tachycines asynamorus), is native to Asia but has spread across much of the world, turning up in basements, greenhouses, and commercial buildings on every inhabited continent. In places like Arkansas, surveys have documented it as the sole introduced rhaphidophorid alongside more than a dozen native species.9Journal of the Arkansas Academy of Science. An Annotated Checklist of the Camel Crickets (Insecta: Orthoptera: Rhaphidophoridae) of Arkansas
The greenhouse camel cricket thrives indoors partly because it is already adapted to a generalist scavenging lifestyle in dark, sheltered habitats, and partly because its gut microbiome, as mentioned earlier, includes bacteria that can break down tough plant fibers. It does not need a carefully curated food source to persist in a building. Cardboard, damp wood, mold, and the occasional dead insect are more than enough. This species is the one most homeowners in temperate regions are encountering when they flip on a basement light and see a cluster of long-legged, humpbacked crickets scatter.
How Native Cave Cricket Diversity Affects Diet
The family Rhaphidophoridae is far more diverse than most people realize. It includes nine subfamilies, with more than half of the global species diversity concentrated in Asia.10Massey Research Online. Lineage to landscape: systematics and evolution of Asian camel crickets (Rhaphidophoridae) In North America alone, the genus Ceuthophilus contains dozens of species that occupy different habitats, from deep limestone caves to forest floor leaf litter to rocky outcrops. Australian species in the genus Speleotettix have been found in limestone caves and even abandoned mineshafts, occupying niches where natural caves are scarce.11Austral Entomology. Integrative taxonomic revision of the Australian cave cricket Speleotettix Chopard, 1944 (Orthoptera: Rhaphidophoridae): New species, distribution and conservation implications
Diet varies with habitat. A species living in a moist limestone cave with seasonal flooding will encounter different food resources than one living under rocks in an arid scrubland. Forest-floor species likely eat more fungal material and leaf litter, while species in bat caves feed heavily on guano. Desert-edge populations may rely more on wind-blown organic debris and animal droppings. The unifying thread is flexibility: across the family, cave crickets eat what is there. Their combination of generalized mouthparts, omnivorous instincts, and a microbial gut community tuned to extract nutrition from poor-quality food lets them colonize environments where specialist feeders would starve.
Practical Steps for Managing Them Indoors
Because cave crickets are driven primarily by moisture and secondarily by food and darkness, indoor management works best when it addresses all three. Reducing humidity below about 60% in basements and crawl spaces removes their main reason for staying. Sealing gaps around foundation walls, pipes, and dryer vents cuts off their entry routes. Removing cardboard boxes stored directly on concrete floors takes away both a food source and a hiding spot.
Sticky traps placed along walls and in corners are the most common direct control method. They work because cave crickets are active at night, traveling along edges, and readily stumble onto glue boards. Chemical pesticides are rarely necessary for cave crickets and tend to be overkill; these insects are not disease vectors and do not reproduce as aggressively indoors as cockroaches or ants. A persistent infestation almost always points back to a moisture problem. Fix the damp, and the crickets will leave on their own or fail to replace themselves as the population ages out. If you are seeing them in large numbers year after year despite humidity control, check for hidden water intrusion: cracked foundation walls, blocked gutters directing runoff against the house, or a crawl space without a vapor barrier are common culprits.
One thing that does not work well is trying to starve them out while leaving the humidity high. Their ability to survive on mold, dust, and the occasional dead bug means a damp basement with no obvious food source is still a viable habitat. The moisture is the lever that matters.