The creature commonly known as the spider cricket, camel cricket, or cave cricket, often causes surprise when encountered indoors due to its sudden, frantic jumping. These insects are instantly recognizable by their extremely long legs and antennae, which give them a distinctly spider-like look. They are typically found in dark, cool, and damp areas. Understanding their natural history and physical traits provides the context for why they seek shelter in human environments.
Defining the Cave Cricket
Spider crickets belong to the insect family Rhaphidophoridae, a large group of wingless Orthopterans known for their unique morphology. Their most distinguishing physical feature is the pronounced, humpbacked shape of their body, which gives them the alternate name, camel cricket. They possess six legs, with the hind pair being disproportionately large and powerful, enabling characteristic long-distance leaps when startled. These insects are typically brown, tan, or reddish-brown, and range from one to one and a half inches in body length. Unlike other familiar crickets, members of this family lack external wings and do not produce the chirping sound often associated with crickets; they rely heavily on their exceptionally long, thin antennae to navigate lightless environments.
Geographic Origins and Native Range
The Rhaphidophoridae family is ancient, with a global distribution that excludes only Antarctica. Their origins are tied to subterranean and forest floor habitats, with many species naturally occurring in undisturbed environments like deep caves, rock crevices, and under forest logs. Native North American species, such as those in the genus Ceuthophilus, have been present in temperate zones for a very long time, adapting to forested and cave-based ecosystems. However, many of the spider crickets most frequently encountered as pests in homes are not native to the continent. The greenhouse camel cricket (Diestrammena asynamora), for instance, is an introduced species that originated in specific regions of Asia, likely China. This and other related species from Asia and Europe have become widespread, establishing populations outside of their original native ranges.
The Path to Global Presence
The modern distribution of non-native spider crickets is primarily a result of human activity and global trade over the last century. Species native to Asia and Europe were accidentally introduced to places like North America and Australia. This spread was facilitated by the transport of freight, goods, and luggage, with the insects or their egg masses hitching rides inside shipping containers and commercial cargo. Once they arrived, their adaptability to various sheltered environments allowed them to establish new populations far from their original homes. The Rhaphidophoridae family is resilient and can survive periods of low resources, which aided their ability to endure long-distance travel.
Preferred Environments and Indoor Infestation
The reason spider crickets “come from” a basement or crawlspace is directly linked to their strong biological need for high humidity. They are highly sensitive to dry conditions and will actively seek out cool, dark, and damp locations to prevent desiccation. This preference often brings them into direct conflict with humans, as the conditions they seek are frequently found in the lower levels of a building. Basements, cellars, crawlspaces, and utility rooms become attractive indoor havens because they maintain a higher moisture content and lower temperature than the outside environment. They may also be found in areas like wells, under woodpiles, or near drainage pipes outdoors. When outdoor conditions become hot and dry, these crickets are driven inside through cracks, vents, or open doors in search of relief and shelter. Once indoors, they are opportunistic scavengers, feeding on a wide variety of materials including decaying organic matter, fungi, mold, cardboard, and fabrics like cotton or wool.