do cockroaches smell like urine?

Why Do Cockroaches Smell So Bad?

Cockroaches produce a musty, oily smell. While it’s usually undetectable by humans, that changes if several roaches – dead or alive – are able to thrive unchecked. In certain quantities, a person may be able to quickly note the presence of an infestation. The longer the roaches are allowed to remain in your home, the more pungent this stink will become.

Roaches smell bad as a result of their pheromones, their death stench, and the environments they like. Roaches use chemical scents to communicate where food, mates, water, and shelter can be found. They also release a death smell that warns other insects to clear away from danger. After that, you’ll see roaches in areas filled with dampness, mold, mildew, and other unpleasant smells. These odors could be accidentally accredited to the insects.

Removing cockroach smells from you home means culling the infestation. After that, you’ll need to thoroughly sanitize the area with chemical-strength products. You may need to throw away food and furniture, as the smell can permanently affect certain items. The scent will not easily fade on its own. Worse yet, if allowed to stay, a roach’s bad smell will only attract more roaches.

Do Cockroaches Make A Bad Smell?

The average cockroach does not produce a smell that’s easily detectable by humans. However, that doesn’t mean they don’t generate odors. In large quantities, people may describe the smell as:

  • Musty
  • Oily
  • Like rancid soy sauce

The good news is, you won’t easily mistake this for other pests. Rats produce a very ammonia-heavy smell, and bed bugs are known for their sweet-smelling odor. Cockroaches, on the other hand, will have a very dry, musty smell.

This odor can be confused with other household problems, but you should be able to distinguish it from other pests.

How Bad Do Cockroaches Smell?

One telltale sign of a serious cockroach infestation is an unexplained stink. You may walk into an old house or a neglected basement and be overwhelmed by the smell. This will be matched to finding droppings and seeing cockroaches.

However, you won’t find the smell arrives overnight. In fact, it may slowly grow over time, undetected as you live in your home. Then, one day, a guest may notice – or you will after being away for some time. That’s because the factors that intensify the smell don’t happen overnight.

These 3 factors will ramp up the situation until even a human nose can sense a problem:

musty roach smell

Many Live Cockroaches

As explained below, roaches use pheromones to communicate with each other. If you have a large colony in your home, this scent-talk may eventually build up. As you uncover a nest, you may be able to smell a pungent musty odor in that area. This is especially true if you pry open their hidey-hole, such as:

  • A pocket in your wall
  • A box they’ve been nesting in
  • Spots beneath appliances or underneath cabinets

Many Dead Cockroaches

Roaches unleash a death scent when they die. This alerts any nearby roaches or other insects that a danger is present there. They can then avoid the spot to avoid getting killed themselves.

This odor is very hard for humans to detect. However, if many cockroaches have been killed in one area, the scent may stack up enough for you to notice it.

Roaches That Are Thriving In Unclean Environments

It’s possible that you’re not smelling the roaches, but the environments they love. These areas are often damp, dark, and prone to growing:

  • Mold
  • Mildew
  • Accumulating other dead insects, which will rot

If a roach colony is able to thrive in this area, of course, they’ll become coated in the damp or mold themselves. It’s possible for them to carry this into other areas of the home. In large populations, enough of the smell may be carted around that humans then detect the odor.

Roaches smell as bad as they’re allowed to. If they’re left to thrive, the odor will get worse. If they’re killed en mass without the use of specialized chemicals, the death scent may spread. That’s why it’s not everyone’s first approach to handle an infestation with a hammer.

What Causes A Cockroach’s Bad Smell?

Roaches themselves don’t automatically smell. In fact, if a roach is kept by itself and not allowed to interact with their favorite smelly foods – like rotting animal carcasses – they’ll be virtually scent-free.

In a home, however, that’s rarely the case. Smells may accumulate for these 4 reasons:

Pheromone Communication

Cockroaches will speak with each other through the use of pheromones, as noted by Biological Sciences. These chemicals are called cuticular hydrocarbons. Since roaches have a powerful sense of smell and are small insects, they don’t need to release much to do the job. These pheromones will help guide a colony to shelter, regulate mating, and warn of danger. However, the bad news for humans is that these chemicals also leave scent trails.

Scent trails can permeate any surface or object they’re exposed to. They can even alter the taste of food, should a roach scent your kitchen leftovers. That can leave an area smelling bad – and, worse yet, tasting bad.  These trails then lead new roaches to safe havens, food, mates, and water. Such trails can and will be detected by other cockroaches, drawing more pests to your home.

The more cockroaches inhabiting a single location, the stronger the chemical scents become. Individual cockroaches may not leave trails detectable by humans. Small colonies will begin to create an odor radius. The more widespread the infestation, the bigger the radius, or the greater number of radiuses in the home.

Do you smell that musty odor? You may have just logged into a colony’s chatroom.

Death Scents

Cockroaches, like bees, do release a chemical odor when they’re killed. Unlike bees, however, it does not indicate that nearby insects and members of their species should become aggressive. Instead, it warns all who detect it that they should run for safety. McMaster University notes that cockroaches actively avoid corpses or areas doused with these chemical scents. There are many possible reasons for this.

The researchers concluded that it likely hinted at the threat of predators, toxic substances, or other deadly elements. One or two roaches cannot release enough of this chemical to alert a human, unless your face is inches from the roach. However, if a large batch dies, you may find the odor stacking. The spots may smell musty or oily over time. Most people clean up the bodies long before this happens.

Should the body be left, a new problem occurs. Cockroaches will rot just like any dead creature. This creates a smell of decay that is unique to them. Other insects may overcome the warning chemical if given enough time. They will then be attracted to the smell of free food in the form of a dead roach.

In fact, certain kinds of toxic bait rely on cannibalism as a method of spreading poisons to other cockroaches. As found by a study in the Journal of Economic Entomology, cockroaches will even eat contaminated cockroach nymphs, which are newly hatched cockroaches.

Whether or not other bugs chow down, in the meantime, you’ll be left with a crisp, musty smell as the roach’s body starts to rot.

Molts And Feces

Roaches unleash most of their pheromone indicators through feces. The poop itself will smell unpleasant, but be hard to notice by humans. The same goes for the pheromones in them. That only changes when – you guessed it – a great deal of poop is allowed to accumulate.

When a cockroach molts, it will also leave its wasted exoskeleton behind. This is odorless, but is still biomass. When it rots, a very limited odor will start to attract other bugs. This can lead them to infesting the area, leaving their own smells and droppings behind.  

If roaches are able to defecate and molt in an area for a long time, undisturbed, the smell may grow. This can help you locate nests or preferred shelter by the colonies. Once you open up a spot, like a hidey-hole in an old box, you may be assaulted by a strong musty smell.

Their Preferred Environments

Roaches like damp, dark, musty areas. This can include:

  • Basements with leaky pipes
  • Boxes with water damage
  • Underneath sinks
  • Drains

Bathrooms that aren’t regularly cleaned are also ideal. These spots will be well loved by mold and mildew, which create a strong odor. Since roaches are attracted to these spots, you may easily confuse the smell of roaches with the smell of:

  • Mold
  • Dampness
  • Mildew
  • Rot

These insects may even let mold grow on their backs, and carry it into new areas. They’ll feast on mildew and chew at rotten areas that have been softened by mold. If you notice that smell, you can consider it part and partial with a roach’s smell. It may not be caused by the cockroaches themselves, but that doesn’t matter. It can still lead you to roaches and help guide your extermination efforts.

Do Cockroaches Smell Like Urine?

Roaches themselves do not produce any smells that are comparable to urine. However, you may confuse the smell of mildew or rot with urine.

The cockroaches may also be coated in urine. Since these pests have no issue walking through unclean areas, there’s no telling what covers their body. They may have invaded a pet’s bathroom pad, litter box, or even their potty spot outside. If you smell a great deal of urine, be sure to check the area for:

  • Rotting food, which can attract roaches.
  • Exposed waste, like a spilled litter box. This is open season for roaches.
  • Areas that may have mold or leaks, such as under the sink. Cockroaches will make this a home.

Do Roaches Smell Like Cat Urine?

Cat urine is a notoriously strong odor, which should catch your attention right away. That’s even truer when you don’t own a cat, and are instead struggling with roaches.

It’s possible that the roaches have gotten in contact with cat urine outside your home. If it’s just one or two roaches, the odor should be too light to detect. If a colony has marched through urine, however, they can easily spread it onto other surfaces. Roaches don’t often clean themselves and are resilient against all bacteria, so there’s no real reason for the urine to ever be washed off.

Aside from that, several kinds of mold produce a smell that’s similar to cat urine. In the same way cat urine is the worst of all urine smells, it could indicate the worst of all mold: black mold. This is a highly toxic substance that will cause long-term damage to people and property alike. Roaches may be living in and around black mold.

When coated in the spores of black mold, they can carry it around your home. This will not only spread your mold problem, but help the roaches thrive. If you smell cat urine and have ruled out a pet, it’s highly recommended to seek out a professional assessment of your home.

Do Cockroaches Smell Like Fish?

Roaches themselves should not smell like fish. However, some people mistake this smell because of their frame of reference. As mentioned, cockroach’s musty odor can be similar to soy sauce, if that soy sauce has gone horribly rancid.

That’s a household condiment typically used in Asian cuisine or, in particular, with sushi. Because of this, most people might smell ‘bad soy sauce’ and think ‘bad fish in the house.’ Roaches themselves are not fishy.

However, in line with the common theme so far, there may be cockroach-friendly problems in your house creating a fish smell.

  • Certain kinds of mold can produce a fishy odor. Roaches like mold.
  • Dead animals, depending on their state of decay, may smell fishy. Roaches are delighted to eat rotting carcasses.  
  • Sewer gases can make a fish smell. Roaches can come from your sewer. These gases being released into your home may indicate there’s a septic tank issue that roaches are exploiting to gain entry into your home.   

Do Cockroaches Smell When You Squish Them?

Roaches will produce a death stench when they’re killed. This may be accompanied by a white, milky liquid if they’re crushed. While some people think it’s the ‘juice’ that creates the death smell, that’s not the case. It’s their blood, which is odorless.

Instead, a chemical acid will be released upon death. In very rare cases, or if you specifically sniff around for it, you may notice this odor. The specific acids responsible for this are oleic acids, or fatty acids. It will smell sharp and pungent.

Crushing the exoskeleton will also expose these acids to the air faster. If you just step on a roach and then smear it, the smell will grow stronger. On one hand, that’s a good way to temporarily scare off more roaches. On the other hand, your own nose may suffer the consequences until the area is sanitized.

Even if a cockroach dies of old age, its decaying body will still release oleic acids. Unless the corpse is removed and surfaces sanitized, the smell will remain. Removing dead cockroaches on sight prevents the smell from becoming ingrained in any surrounding objects or surfaces.

how to get rid of cockroach smell

How To Get Rid Of Cockroach Smell

When tackling cockroach odor removal, you need to be thorough. Even if you have eradicated the infestation, the stink of cockroaches will still linger. That’s especially true if it was a long-standing population.

If left alone, the smell will eventually attract more roaches and create the same problem once again. That’s not to mention the unpleasantness of living in those conditions yourself. As such, you can take these steps.

Pest Control

Depending on the service, most pest control companies will remove dead cockroaches from your property. They can also sanitize the area and lay down repellents to deter any new, opportunistic roaches.

Remove The Bodies

However, if you don’t want to invest in a pest control company, there are DIY solutions. The key will be to completely purge any evidence of the old colony. Any remaining corpses should be cleaned up and disposed of with haste.

  • Be sure to wear gloves and a mask. The insecticides or the dead roaches themselves may irritate the skin or trigger breathing issues.
  • If you put the corpses in the trash, immediately take out the trash to be disposed of by your garbage service.
  • If you flush roaches down the toilet, be sure they’re dead and then clean the toilet as well.

If you crushed the roaches, this should include any stray limbs, exoskeletons, or antennae. Nothing should be left behind or considered too minor.

Vacuum The Floors, Cupboards, Shelves, And Furniture

Clean up any droppings and molted shells as well. These can all leave smells behind. A vacuum is highly recommended, as it will more thoroughly suck up any remnants. A broom or mop may only spread the smell around. It is also suggested to run your vacuum along:

  • The tops of cupboards
  • Shelves
  • Under and behind all furniture

Even a few traces could encourage new roaches to come sniffing around.  

Throw Away Roach Shelters

Any items that the cockroaches were living in or near should be disposed of. This may include:

  • Boxes
  • Plastic containers
  • Bedding or clothes
  • Bags


Anything left, or anything which can’t be disposed of, should be thoroughly disinfected with chemical-strength disinfectants. This will include clothing, furniture, or walls.

Bleach can be used in kitchen areas or places where color damage isn’t an issue. For cloth or furniture, you can use pet-safe sprays or sanitizers.

  • Spray down areas where the cockroaches lived with a disinfectant
  • Let it sit for 10-15 minutes
  • Wipe everything down and repeat if necessary

It’s recommended to air the space out once you’re finished. The overpowering scent of disinfectant will be helpful against roaches, but you shouldn’t harm yourself.  

Shampoo And Scrub

If you have carpets or rugs, source a cleaner specific to these surfaces that will do the job. As the cockroach stink can thoroughly embed itself in surfaces, you may have to permanently dispose of some objects if the stink can’t be lifted.

Remove Attractants

Getting rid of cockroach smells also means preventing new cockroaches from settling in your home. This involves getting rid of any chemical trails with the above methods, and also making your home unattractive to visiting pests.

To do this, you need to deprive the cockroaches of food, water, and places to nest in. Regularly removing trash and cleaning bins of food scraps is also important.

Throw Out All Contaminant Food

Given that the cockroach smells can infect food and alter its taste, we strongly recommend throwing all contaminated food away. Not doing so can pose a serious health risk.

While the scent markings themselves may not be deadly, it indicates roaches were crawling through the food. The bacteria which coats them can prove lethal, especially to people in risk groups.

Do Cockroach Scents Fade?

In theory, cockroach scents will fade in time. They’re not powerful enough to last forever. With that said, it’s just a theory, because no roach will ever pass up a chance to follow a scent trail. If you leave a bad cockroach smell in your home, you will only attract more cockroaches. Sadly, you can’t wait for the problem to resolve itself.

Depending on the severity of the infestation, wallpaper and even segments of drywall may need to be removed and replaced. Wood soaks up chemical scents easily, and removing cockroach stench can be costly.

Once a cockroach begins leaving scent markings, others will hone in and create a colony. These smells are not known to be hazardous, but they are unpleasant. Stripping these chemical trails from your home requires intensive cleaning and sanitization. Once you’ve done so, you can go back to a clean, pleasant-smelling home.