Are Cockroaches Clean?

Cockroach climbing on shower wallCockroaches are undoubtedly the most unpleasant and disgusting creatures to crawl on the earth. Whenever we think of cockroaches, we associate them with a dirty and disgusting environment. But are they clean?

Cockroaches usually survive on filth and dirt, such as garbage, dumpsters, and leftover food. So, it is nearly impossible to see them following a cleaning regime. However, despite that, these creatures tend to have a cleaning habit. Surprising, right?

Let’s discover how and why cockroaches clean themselves.

Are Cockroaches Dirty?

Cockroaches are dirty, mainly because they are not picky eaters. They will eat anything available to them. From pet dander to food leftovers, cockroaches do not mind feasting on anything.

Another factor that makes cockroaches dirty is they survive under high-moisture and humid conditions. Your home, especially the bathroom and basement, provides cockroaches with the perfect temperature to thrive. As a result, they are primarily found in the bathrooms, under the sink, in kitchens, and in dark areas.

So, any animal that spends most of its time in the bathroom isn’t clean. Cockroaches also prefer a dark place. It means sewer lines, pipes, and garbage are the ideal places for cockroaches to live.

As mentioned above, cockroaches usually live in unsanitary and moist areas. Such conditions attract them to fermented foods and molds. Hence, they are exposed to numerous pathogens and microbes.

Medical research shows cockroaches are a reservoir for different kinds of bacteria, including salmonella, staphylococcus, and streptococcus. They can also spread viruses, such as:

  • Polio Virus
  • Chlora
  • Dynasty
  • Leprosy

Bacteria can be carried on the cockroach’s cuticle. Later, this ingested bacteria can survive inside the body of a cockroach. They can easily transmit these bacteria to your food, kitchen areas, bathroom surface, utensils, and other areas.

Cockroaches can also contaminate your food by leaving these bacteria through vomiting or defecating, leading to food poisoning and diarrhea.

Do Cockroaches Clean Themselves?

No one would expect these filthy insects to have a cleaning routine. But, regardless of their surroundings filled with rotting food, garbage, and feces, they clean themselves regularly.

According to research by Scientific World Journal, cockroaches have an innate behavior of self-grooming, meaning they are genetically connected to cleaning themselves.

The Experts Say: Cockroaches Groom Themselves Like Cats

A bug collector named Darrin Vernier said that cockroaches are like cats. Both creatures self-groom themselves. There are around 4,000 species of cockroaches in the world. And luckily, not all of them are dirty.

Some cockroach species do not infest homes or visit unsanitary areas. Hence, they are not considered dirty. These species usually live outside, near bushes and trees and feed on leaves and other organic food. These include:

On the other hand, some common cockroach species are of the filthiest kinds. They live inside unsanitary areas, such as bathrooms, commodes, sewer lines, and garbage, meaning they can transmit diseases. These include:

  • American cockroach
  • German cockroach
  • Oriental cockroach
  • Brown-banded cockroach
Cockroach Type
American Cockroach Indoors and Outdoors Everything Dirty
German Cockroach Sewers and Outdoors Filth Dirty
Oriental Cockroach Sewers and Outdoors Filth Dirty
Brown-banded Cockroach Indoors and Sewers Filth Dirty
Discoid Cockroach Outdoors Rotted leaves and organic matter Not dirty
Dubia Cockroach Outdoors Rotted leaves and vegetables Not dirty

How Do Cockroaches Clean Themselves?

Cockroaches perform a cleaning regime multiple times a day. Their cleaning process is quick. They tug their legs and antennae in a rapid bouncy movement. During this short cleaning session, here is what happens:

  • First, the cockroach pulls its antennae into its mouth.
  • Then, it brushes the legs on their face, neck, and abdomen.
  • Lastly, it puts its legs through its mouth.

This mostly happens when a cockroach comes in contact with dirt, bacteria, or other sticking materials. Then, they take short intervals to clean their antennae and ensure their smell, auditory, and visual senses are clean.

The grooming session of cockroaches is very similar to other insects, such as flies.

Cockroaches are small insects; they can’t splash in the water, nor can they dig a hole in the dirt. Hence, they rely on their internal secretion, saliva, to get rid of the dirt and debris from their bodies.

Why Do Cockroaches Clean Themselves?

A group of researchers from the Russian Academy of Science and North Carolina State University studied why cockroaches clean themselves using their antennae. They assumed that the buildup substance on the cockroach’s body could reduce the olfactory abilities of its antennae.

The study showed cockroaches with cleaned and dirty antennae to smell food and sex pheromones. They also found that cockroaches with cleaned antennae were more active and responsive to the triggers than other groups.

Furthermore, the researchers also studied the ungroomed antennae to find out what exactly cockroaches clean off. As it turns out, in addition to the buildup of dirt and dust, cockroaches also gather cuticular hydrocarbons in their antennae.

Cuticular hydrocarbons are fat particles secreted by the cockroaches for water loss regulation. Sometimes this secretion clogs their antennae, making it difficult for them to sense.

Do Cockroaches Clean Themselves After Touching Humans?

Cockroaches clean themselves after coming in contact with humans. Not because they think humans are dirty, but only because they habitually self-groom after touching anything.

Cockroaches are dirty scavengers; considering they feed on anything and live near unsanitary areas, it is easy for their antennae and legs to be built-up with dirt.

Therefore, they clean themselves after anything they touch to avoid weakening their senses. This is their innate behavior.


Are Cockroaches Clean Creatures?

Yes, cockroaches are clean creatures. Even though cockroaches are known for living in dirty places and contaminating our food, they clean themselves multiple times a day. Regardless of their dirty diet and filthy habitat, they prefer removing any buildup of dirt from their body to prevent their olfactory senses from weakening.

Are All Cockroaches Dirty?

No, not all cockroaches are dirty. There are 4,500 species of cockroaches in the world. Every species of cockroach is dangerous to human health. However, not all of them are dirty in general. Only 30 species out of the total count are considered pests, making up only 1% of the species.

The dirtiest cockroaches are:

  • American cockroach
  • German cockroach
  • Australian cockroach
  • Oriental cockroach
  • Brown-banded cockroach

What is the Dirtiest Cockroach?

Oriental cockroaches, also called “water bugs,” are the dirtiest cockroaches. They live in drains and sewers. They leave behind various bacteria wherever they go and carry a strong, pungent odor.

What Happens If a Cockroach Doesn’t Clean Itself?

Cockroaches clean themselves by brushing their legs and antennae in their mouth. It eliminates the buildup material and allows them to function properly. However, if a cockroach doesn’t clean itself, the antennae and legs will be filled with environmental buildup, which can lead to weak senses. As a result, a cockroach will be:

  • Unable to smell food
  • Difficulty in mating
  • Inability to stay away from a predator


Grooming is a common process insects perform to clean themselves. Every insect, including cockroaches, cleans themselves for the same purpose – to maintain optimal function of their olfactory senses to hunt food, locate a mate, and sense danger.

Among 4,500 species of cockroaches, the most dangerous and dirtiest ones are:

  • American cockroach
  • German cockroach
  • Australian cockroach
  • Oriental cockroach
  • Brown-banded cockroach

On the other hand, the cockroaches that are not considered dirty include:

  • Discoid cockroaches
  • Dubia cockroaches
  • Red runner cockroaches
  • Wood cockroaches
  • Black-bettle cockroaches

Nevertheless, it is crucial to keep your home free from cockroaches. Whether an American cockroach or the dubia roach, it’s always safe to use an insecticide.