It is often said that cockroaches are incredibly durable and hard-to-kill insects that can survive severe physical trauma and highly toxic environmental conditions that would instantly kill any other terrestrial organism. The claim that cockroaches can withstand nuclear fallout and survive for weeks after being decapitated are two commonly uttered claims that many people naturally find dubious. However, experts say that there is some truth to these claims. For example, since cockroaches have an open circulatory system that lacks an intricate network of blood vessels, and since they can survive long periods of time without food and water, a cockroach can, in fact, go on living for weeks without the benefit of its head.

Cockroaches can continue to breathe after being decapitated, as they breathe through many little holes on their body known as “spiracles.” After a cockroach head is severed, blood quickly clots, which prevents them from bleeding out, and their nervous system is not regulated by a central organ located in their head; instead, their nervous system is spread throughout their body. Amazingly, even a detached roach head can go on functioning for a period of time as evidenced by the movement of their antennae post decapitation. Research has demonstrated that around 10 percent of roaches within a given population can survive high radiation levels after the detonation of a nuclear weapon, which makes it easy to understand why roaches are so resilient to the toxic effects of insecticides.

Cockroaches owe their resilience to their primitive nervous system, as their cells divide much more slowly than human and other animal cells. This allows a roach’s cellular chemistry more time to repair genetic damage caused by radiation, insecticides, and any other toxic compounds that they may become exposed to within their environment. Recent research suggests that cockroaches may be able to avoid the toxic effects of insecticides by sealing their spiracles in order to avoid breathing for periods lasting as long as seven minutes. While cockroaches may be relatively challenging to eradicate from infested homes, many recently developed baiting systems and insecticide dusts have proven effective at eliminating even particularly heavy roach infestations.

Have you ever encountered a roach that managed to survive being directly sprayed with over-the-counter aerosol insecticides?