Many people consider cockroaches silent, but a common misconception is that all species are noiseless. Though typical household cockroaches generally don’t produce audible sounds, certain types do create distinct noises. These sounds offer a glimpse into their diverse behaviors.
The Sounds Cockroaches Produce
Some cockroach species produce audible sounds, with hissing being one of the most recognized. The Madagascar Hissing Cockroach (Gromphadorhina portentosa) is a prominent example, known for loud hisses. This sound is generated by rapidly expelling air through specialized respiratory openings called spiracles on its abdomen, a mechanism unique among insects as most others produce sounds by rubbing body parts together or vibrating membranes. The hissing can be pronounced, sometimes compared to a cat’s hiss or a rattlesnake’s tail. Other species, like the Giant Burrowing Cockroach (Macropanesthia rhinoceros) from Australia, also hiss by expelling air from their spiracles when threatened.
Beyond hissing, some cockroaches create chirping sounds through a process known as stridulation. This involves rubbing specific body parts together, similar to how crickets chirp. For instance, male cockroaches might rub their pronotum (the plate-like structure covering the thorax) against their costal veins to chirp. Species like Henschoutedenia epilamproides have a stridulatory organ between their thorax and abdomen, producing distinctive sound patterns when disturbed. Less common, certain species may also produce subtle clicking or tapping sounds from movement or interaction with surfaces. These are usually incidental, not deliberate communication.
The Purpose Behind Cockroach Sounds
Cockroach sounds serve various behavioral functions, primarily communication. One purpose is in mating rituals, where males use sounds to attract females and establish presence. Male Madagascar Hissing Cockroaches, for instance, emit specific hisses during courtship, influencing female receptivity. Research indicates that if these males are muted, mating success can be reduced, highlighting the importance of these acoustic signals. Similarly, chirping sounds from some species are often part of male courtship behavior, signaling suitability to potential mates.
Cockroach sounds also function as warning signals or defense. When disturbed or threatened, species like the Madagascar Hissing Cockroach produce a sharp alarm hiss to startle predators and alert other cockroaches to danger, allowing escape. Aggressive hisses are also used in male-on-male interactions to assert dominance or defend territory, like burrows or breeding rights. These communicative sounds are primarily observed in specific, often larger or exotic, cockroach species. Common household cockroaches, like the German or American cockroach, do not produce deliberate, audible sounds; any noises are usually incidental to their movement.