Cockroaches are seen as filthy bugs that spread disease and bacteria. They come into contact with garbage, rotting food, poop, or even bodily fluids regularly. Roaches will even pack around mold spores and fungus accidentally, spreading it throughout your home. With all that in mind, it seems outlandish that roaches have their own cleaning routine.
Cockroaches do clean themselves. They will run their antennae and legs through their mouths, licking away the filth. This removes dirt, sticky substances, and rotting matter. This grooming routine helps cockroaches keep their bodies clean, so they can navigate and forage more effectively. However, it doesn’t limit the amount of bacteria that spreads between the roach’s saliva and the rest of its body.
In the wild, roaches mostly interact with decaying wood or leaves, which means less exposure to bacteria. Some species even use their poop to slow the growth of fungus in their nests. While roaches may not be objectively cleaner than humans, they don’t like to wallow in filth.
- 1 Are Cockroaches Dirty?
- 2 Are Cockroaches Cleaner Than Humans?
- 3 How Do Cockroaches Clean Themselves?
- 4 When Do Cockroaches Need To Groom Themselves?
- 5 Do Cockroaches Really Clean Themselves After Touching Humans?
Are Cockroaches Dirty?
Cockroaches are not inherently dirty. In the wild or when bred in captivity, roaches are as clean as any other bug. What makes your household roach so filthy are the parasites and bacteria they pick up around your home. For example, an infestation will give your roaches the chance to walk through:
- Rotting food
- Cleaning chemicals
This will coat the insects in bacteria, diseases, and even mold spores. If they survive exposure to insecticides, the roaches will then pack around these chemicals and spread them to other surfaces. If they spread this to your food, you can face health risks.
Because of that, if you find a cockroach in your house, it’s likely to be dirty. It can spread filth along foraging routes, and pile up contagents in its nest. However, this usually isn’t the case for wild roaches.
In their natural habitats, wild cockroaches routinely avoid filth and limit their contact with fungus. They may eat rotting wood, carcasses, and decaying matter. However, they will clean their feet and antennae after exposure to it. This doesn’t make every wild roach squeaky clean, but it doesn’t make them a serious vector for disease like their household cousins.
Even in your home, roaches work to clean their antennae, feet, and body to remove the filth. The only trouble is, they can’t remove all the bacteria or pesticides. This makes normal roaches a big threat to your home, no matter how tidy they try to keep themselves.
Do Roaches Clean Away Fungus?
Roaches prioritize cleanliness for themselves, but also for their nests. Because fungus is such a big threat to cockroaches, some species, like the wood roach, even use poop to cleanse their nests, according to Natural Sciences. After all, if they’re not eaten by a predator, fungus is one of the only things that will kill a roach. It’s evolutionarily wise to develop a defense mechanism against this.
Researchers studied wood roaches in a closed environment to see how they reacted to fungi. The test involved entomopathogenic fungus, specifically called Metarhizium anisopliae. This was placed in a container with a roach nest and lightly incubated to encourage its growth. Cockroaches poop often, so the fungus immediately came into contact with the feces.
Once the feces were incubated, the growth rate of the fungus slowed exponentially. That’s right – roach poop can actively dampen how quickly fungus grows. At first, it was believed that the enzymes in a wood roach’s gut were actually responsible for harming the fungus. However, with prolonged exposure, it was discovered that the gut bacteria of these roaches lacked any enzymatic function.
Poop alone couldn’t do the job. Instead, it was exposure to heat that made the poop suddenly develop anti-fungal properties. Researchers aren’t sure which microbial is responsible for this, but theories have spread. It’s possible that an early ancestor of wood roaches and termites evolved this trait to disrupt the chemical balance of fungus. This kept their nests clean and free of all the little microbes that could harm the species.
Of course, the feces must be properly incubated to gain this ability. This isn’t a hindering factor for most roaches, however. Roaches typically like warm and balmy areas. Their environment naturally kicks the anti-fungal properties of their poop into gear.
Are Cockroaches Cleaner Than Humans?
At a glance, roaches are not cleaner than humans. Household varieties have more exposure to pesticides, bacteria, and rotting matter that carries disease. Worse yet, this filth doesn’t just coat a roach’s outer body. It will infect their saliva and poop, allowing them to easily spread it. The average person doesn’t go rooting around in garbage and dead animals, so we do not carry the same bacteria.
Because of that, while roaches aren’t venomous, a bite from one can be dangerous to humans. Their mandibles are used to pull away at the rotting matter and chew up decaying food. This coats the insect in bacteria, and when it bites you, the bacteria transfer to your skin. This can lead to infections and rashes, if not more serious reactions.
However, if we zoom out from microbiology and look at how much tangible filth is on a roach, they may be cleaner than humans. Roaches take several moments each day to clean themselves. They will lick their antennae and scrape away filth from their legs. A human may only shower once a day, but roaches groom themselves countless times each day. In this sense, roaches do have a more strict cleaning routine than people.
Depending on the person, and the roach, these bugs may be cleaner than humans. That’s especially true for wood roaches and species like them. They will only come into contact with the decaying wood, and limit their exposure to other bacteria. On the flip side, a human may pick up bacteria from the bathroom, kitchen, and public areas throughout the day. If you only bathe every few days, a wood roach might be cleaner than you.
Roaches can’t wash off all their bacteria. Even their hard exterior shells work as an allergen for people and other animals. Although roaches aren’t bothered by the allergens, mold spores, or bacteria they carry, other creatures are. Because of this, you can’t trust a roach’s cleaning routine to automatically make it safe to touch, interact with, or feed to a pet.
How Do Cockroaches Clean Themselves?
Cockroaches perform a cleaning routine multiple times a day. According to the Journal of Comparative Neurology, this habit is controlled by the insect’s neurons. They fire signals to the legs and mouth, so they all work in tandem.
Roaches clean at a fast pace, tugging their legs and antennae in quick, jerky movements. During this short grooming session, a roach will:
- Slow to a stop
- Pull their antennae into their mouths
- Brush their legs over their face and abdomen
- Run their legs through their mouths
It resembles the way that flies and other insects groom themselves. To a distant extent, you can even match it to how a cat will clean itself. Roaches do not splash in water like birds, and they do not roll around in dirt like some mammals. Instead, they rely on the saliva in their mouths to clean away the filth that’s gathered on their bodies.
Of course, for a household roach, this can spread the bacteria from their saliva to the rest of their body, and vice versa. However, they will also be cleaning away tangible dirt, food leftovers, and even fungus. This accomplishes 2 purposes:
- It removes a build-up of filth, so the roach isn’t overwhelmed by bacteria or mold
- It removes any caked-on material from their antennae and legs
A layer of anything on the antennae will hamper a cockroach’s ability to navigate. They will tap and wave their antennae around food, garbage, and feces to learn different things about them. This may include smell, size, and nutritional content. However, in doing so, the bugs may get lots of debris all over their antennae.
This would otherwise block the sensitivity of the appendage and make it harder to navigate in the future. To stop this, roaches make a pit-stop and clean away the extra. This also applies to their legs, so the small hooks that give roaches their dexterity are not impeded.
When Do Cockroaches Need To Groom Themselves?
Roaches need to groom themselves whenever they’ve been exposed to filth. This happens constantly, so roaches don’t just wait around for the right time. Instead, they groom themselves whenever they’re not busy foraging, breeding, or exploring. Some will even pause in the middle of a feast to clean off their legs and antennae, should they get overly dirty throughout the meal.
According to The Scientific World Journal, roaches also clean themselves in response to small particles, irritants, and parasites. If the bug finds a sticky substance on its body annoying, for example, it may stop to remove the problem with a speed-clean.
If the roach gets coated in filth right after its last cleaning routine, it will stop and clean again. This may happen after it’s walked through spilled juice in your kitchen, or as it explores your pet’s litter box. If a roach touches a person and gets the smell of essential oils or perfume on its body, it may pause to clean itself after it’s fled for safety.
It mostly depends on the individual roach and its preferences. If it decides its antennae and legs are too dirty, and it’s struggling to navigate, it will take a pit stop at its leisure. Other roaches may seem caked with filth or bacteria, but so long as it doesn’t affect their ability to function, they may postpone cleaning.
After all, sometimes it’s better to locate new food, run from danger, or engage in mating at that exact moment. Grooming can wait.
How Often Do Cockroaches Clean Themselves?
Roaches groom themselves constantly, to the point where it may even appear obsessive. That’s because they prefer multiple small grooming sessions, instead of one big session. Likewise, because they’re exposed to filth regularly, they have to maintain a strict schedule to keep up with that.
Roaches mostly groom themselves during peak hours, when they’re exposed to the most filth. This is not only when they forage, explore, and eat, thereby touching a lot of bacteria-ridden surfaces. It’s also when roaches have the most energy, so they can take pit stops to groom themselves along the way.
Peak hours for a roach are during the night, at around 2-4 hours after sunset. If your home has a late bedtime, the roaches may wait until the household gets quiet before foraging and grooming. If you spot a roach sitting in one place, without moving, it’s likely cleaning itself.
Some brands of pesticide use this to their advantage. A roach’s exoskeleton is very thick and resilient. It may be difficult for any poison to seep in and cause damage. To get around that, insecticides will cling to the legs and antennae of a roach, and wait. Once the roach grooms itself and licks off the poison, it’s officially eaten the neurotoxins and the poison can get to work.
Do Cockroaches Really Clean Themselves After Touching Humans?
Roaches do clean themselves after touching a human. However, it’s not because they find people to be exceptionally dirty. You won’t see a roach frantically trying to clean off a human smell, or avoiding us because of dreaded ‘human’ bacteria. Instead, they will clean themselves after contact with any predator.
Roaches know they need to limit their contact with fungus, bacteria, and mold. Considering what they eat and where they travel, this would quickly build up on their legs and antennae. To avoid being overwhelmed, to the point of even placing their own lives in danger, roaches clean themselves often. It’s a natural habit and a natural response to being in contact with another creature.
As such, roaches clean themselves after touching humans, but not because they touched humans. It’s just a routine action that allows the bug to wash off any old or new filth that it’s picked up along the way.
Are Roaches Grossed Out By Humans?
You may believe that part of why roaches flee from people is the bacteria we present. Some people even claim that roaches can tell when you’re clean or dirty, and will avoid or target you as a response. In reality, cockroaches flee from humans because:
- We’re larger than they are
- We’re louder than they are
- We surprise them with light or movement
- We’re covered in scents they dislike
That last point explains why roaches might avoid some people and be braver with others. If your home is being overwhelmed by an infestation, for example, roaches might explore your roommate’s bed, but not your own. In this case, it’s possible that the cockroaches dislike your roommate’s:
- Perfume or cologne
- Fabric softener, especially if it smells like lemongrass or rosemary
- Air freshener, especially if it’s citrus
Roaches do not find these smells dangerous. They just dislike the powerful scents and will try to avoid them. It’s not a matter of your roommate being cleaner or dirtier; it’s a matter of wearing or spraying accidental cockroach repellents.
Roaches clean themselves regularly, even if they’re dirty creatures. They prioritize removing filth, but their grooming routine can’t do away with bacteria entirely. That makes it important to clean out an infestation before it can spread disease.