Cockroach Natural History

When most people see a cockroach, their first instinct is “ewwww gross!” Cockroaches are associated with decay, grime, and uncleanliness and have been known to spread germs and other harmful bacteria.

Despite their negative reputation, cockroaches are one of the most interesting and resilient pests in the world. Cockroaches have existed for at least one hundred million years and are older than most dinosaurs. So today, we are going to cover this famous, creepy, crawling insect and talk about what makes cockroaches special. 

Credit: Pixabay

Cockroach Anatomy

The average cockroach is about the size of a regular human thumb, but some species can grow to the size of your entire hand. They have characteristically flat bodies and most species are a shade of brown or brownish-red. Like all insects, cockroaches have compound eyes, a pair of antennae, and six legs—2 per body segment.

Similar to beetles, cockroaches have a set of hardened tegmina that cover and protect their wings. The cockroach’s abdomen is coated in a wax-like substance that repels water and is dotted with spiracles for oxygen transfer.

Cockroach Behavior/Diet

Cockroaches are highly social insects and are noted for their gregarious behavior. Scientists believe that cockroaches use pheromones to attract one another and differentiate between populations.


Similar to schools of fish, a swarm of cockroaches can exhibit interesting emergent behavior based on a set of simple interactions. A swarm of cockroaches can “choose” which food source to pursue by each roach following the cues of its neighbors. This kind of aggregate behavior creates complex social ties among roach populations. Similar to ants, roaches have a high level of social dependence and exchange information with one another. However, unlike ants, roaches do not appear to have task specialization.

Cockroaches inhabit a wide range of climates, so their diets vary based on location and geography. Most cockroaches are omnivorous and eat fruit, vegetation, dead insects, skin, starches, paper, and even glue. Cockroaches will eat virtually anything, which is one reason they are such bothersome pests.

Cockroaches & Humans

Cockroaches and humans share a long history; so long in fact that some species of cockroaches have adapted to subsisting entirely off human waste. Cockroaches are a common pest and can spread harmful pathogens such as cholera, dysentery, and salmonella.

Credit: Pixabay

Despite their negative associations in the West, many cultures around the world eat roaches. Cockroaches are frequently used in scientific studies due to their hardiness, and ease of breeding. Scientists use cockroaches to study all kinds of topics, such as pheromones, biological rhythms, sexual selection, and more.

Interesting Facts About Cockroaches

  • A cockroach can survive with its head cut off for nearly a week
  • Cockroaches have a significantly higher radiation tolerance than many other insects
  • Cockroaches can survive for a month without any food or water
  • An adult cockroach can run up to three miles an hour
  • Some American species of cockroaches have developed a taste for alcoholic beverages
  • A cockroach named Nadezhda was the first terrestrial animal to reproduce in space as part of the Russian Foton-M mission.