The question of whether a cockroach screams when it dies arises from unsettling sounds heard when the insect is crushed or exposed to chemicals. The simple answer is that cockroaches, or any other insect, lack the biological structures required to produce a scream like a mammal. The belief that the insect is vocalizing in distress misunderstands insect physiology and the mechanical sounds that occur during physical trauma.
The Source of the Misleading Sound
The noises people associate with a “scream” during a cockroach’s death are mechanical in nature. When a cockroach is crushed, the most audible sound is the distinct cracking or crunching of its rigid exoskeleton. This sound is the physical fracturing of the tough external cuticle, which provides the insect with structural support.
A different, high-pitched squeal or hiss can occur, especially when using aerosol pesticides or heat. This sound results from forced air expulsion from the insect’s body. Cockroaches, like all insects, have a respiratory system that is highly pressurized with air.
When the body cavity is suddenly compressed or muscles spasm due to chemical exposure, the air inside is rapidly forced out. This involuntary expulsion happens through the insect’s breathing holes, creating a whistling or hissing noise. This noise is merely an uncontrolled physical reaction, similar to the sound of a balloon popping.
Biological Limitations to Producing Vocal Sounds
Cockroaches are physically incapable of producing a modulated vocalization like a scream because they lack the necessary anatomy. Unlike vertebrates, which rely on lungs, a diaphragm, and a larynx containing vocal cords, the cockroach respiratory system is decentralized. They do not possess a single set of lungs to push air across vocal membranes.
Instead, they use a system of tubes called tracheae that branch throughout their body, delivering oxygen directly to tissues and cells. This network connects to the outside world through small openings called spiracles, located along the sides of the thorax and abdomen. These spiracles are purely for gas exchange and are not designed for complex sound modulation.
A scream requires a creature to control the flow of air over specialized tissues to generate variable pitch and volume. Cockroaches lack the muscular control and the vocal structures to create such a sound. Their respiratory architecture is fundamentally different from that of an animal capable of true vocal distress.
Other Noises Cockroaches Produce
While they do not scream, some cockroach species intentionally produce sounds for communication. The most famous example is the Madagascar Hissing Cockroach (Gromphadorhina portentosa), which uses modified spiracles to create a loud defensive hiss. This hissing is used to startle predators or to communicate during mating rituals and territorial disputes.
Other common household species may produce subtle clicking or chirping sounds. These noises are generated through stridulation, a process where the cockroach rubs together specialized body parts, like wings or segments of the exoskeleton. These communicative sounds are often related to courtship or threat displays. The familiar rustling or scuttling sound is created by their legs dragging across surfaces.