The cave cricket (Rhaphidophora spp.) is among the most abundant animals in the darker sections of Niah's Great Cave. These pale, hunched insects — up to 6 cm in body length with antennae three times that length — cover the cave walls in their thousands in the innermost chambers, moving slowly over the guano floor and the rock face in search of organic material. They are the cave ecosystem's primary scavengers, consuming bat droppings, dead insects, and the carcasses of cave animals.
Cave crickets have evolved dramatically from their surface relatives. Their eyes are vestigial or entirely absent — useless in total darkness. In compensation, their antennae are extraordinarily elongated, sometimes reaching 20 cm, providing chemical and tactile information about the environment that sight would otherwise supply. Their legs are long and carry an array of sensory hairs. They are slow-moving, flightless (their wings are reduced or absent), and pale — lacking any pigment that would have no function without light.
The cave cricket is a critical link in Niah's cave food web. It processes the enormous quantity of guano produced by millions of wrinkle-lipped bats and swiftlets, breaking it down into smaller particles and making nutrients available to bacteria and fungi. In turn, the crickets are prey for cave spiders (including a species of huntsman spider specialised for cave conditions), snakes (particularly the cave racer, Elaphe taeniura), and cockroaches.
Visitors on the boardwalk trail who look carefully at the cave walls in the dim light of the Great Cave will see crickets moving across the surface. They are completely harmless and are not disturbed by the presence of humans — they have few predators that hunt by sight and have lost the escape reflexes that surface crickets rely on. In the deepest sections, near the Painted Cave trail, the density of crickets on the cave floor reaches thousands per square metre — a testament to the productivity of the guano substrate beneath them.