Are Cockroaches Dangerous?

Written by Cindy Rasmussen
Published: April 2, 2022
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When you consider where cockroaches live; sewers, city dumps, latrines, and sewage treatment plants, you can understand why you would not want one crawling on your kitchen counter. These bugs are definitely unsightly but are cockroaches dangerous? Do cockroaches bite? Are they poisonous? Do they carry diseases? Let’s find out more about this common pest.

Does Bleach Kill Cockroaches - Dead Cockroach

Cockroaches live in sewers and city dumps.


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What is a cockroach?

A cockroach is an insect that has a reputation for being an annoying household pest. There are over 4,600 species of roaches with a few species that are most commonly found in homes, restaurants, bakeries, and commercial buildings. They prefer warm moist habitats which is why they commonly live in sewers and sewage treatment plants.

What kind of cockroaches is the most common in the United States?

The American cockroach can grow to be 1.5-2 inches long.

©Gary Alpert at the English language Wikipedia / Creative Commons

  • American cockroach (Periplaneta americana): The American cockroach is not from America, it is from Africa and the Middle East but has made its way into the United States and spread throughout the country. It is a flat, oval insect about 1.5-2 inches long with a reddish-brown body. The American cockroaches are the largest of the cockroaches that are considered household pests. Their legs look like they are covered in tiny spikes and they have long antennae. Both the females and males have wings but they are not great flyers. It is much more common to see one scooting across the floor.
  • Brown-banded cockroach (Supella longipalpa): These cockroaches are similar to the American cockroach but are smaller the females have wings but they cannot fly, the males can. They get their name from the two light-colored bands that go across their backs.
  • German cockroach (Blattella germanica): These are smaller cockroaches that don’t get much bigger than a half-inch. They also have two bands on their backs, but their bands are a little darker than the brown-banded. The German cockroach reproduces the fastest so they can get out of control quickly. Because of their small size, they are more easily spread and can hitch a ride home from the grocery store in bags.
  • Oriental cockroach (Blatta orientalis): The oriental cockroaches are originally from Asia and have spread through much of the US. Not quite as big as American cockroaches but much bigger than the German or Brown-banded at 1-1.5 inches. They are also darker in color with some being a shiny black color. These have a reputation of being the dirtiest cockroach.

Do cockroaches bite?

No, cockroaches rarely bite humans. They have mouthparts and are capable of biting but being bit by a cockroach is extremely rare.

Are cockroaches poisonous?

No, cockroaches are not poisonous or venomous. They do not have any poison or venom.

Are cockroaches dangerous?

Cockroaches are dangerous because they carry bacteria. They can cause intestinal disease, allergies, and infection if they scratch you.

What bacteria do cockroaches carry?

Going back to where cockroaches live, it makes sense that they carry lots of bacteria. They may live in the sewer and then come inside your home when the weather gets cooler, bringing along on their legs and body everything they walked through in the sewer. Cockroaches often live and migrate in groups so you are now talking about a small group of 5-10 or a large infestation of 100. Some of the bacteria that have been found on cockroaches include salmonella, staphylococcus, and streptococcus.

How do cockroaches spread bacteria?

Cockroach Infestation - Cockroach in kitchen

Cockroaches can spread their bacteria by walking on kitchen counters and utensils.


Cockroaches spread bacteria by walking on surfaces like kitchen counters and restaurant prep tables used to prepare food. They can spread their bacteria through their foul-smelling feces, leaving droppings on kitchen utensils and dishes. When people ingest food or drink that has been infected by the bacteria they can get sick.

What intestinal diseases do cockroaches cause?

Cockroaches can be dangerous because they can cause food poisoning. One reason health inspectors target cockroach prevention in restaurants and grocery stores is that contaminated food can cause a variety of intestinal diseases. According to the World Health Organization cockroaches can be “carriers of intestinal diseases, such as diarrhea, dysentery, typhoid fever and cholera.”  Exposure to bacteria can cause symptoms of food poisoning like:

  • Upset stomach
  • Nausea
  • Diarrhea
  • Vomiting
  • Dehydration
  • Fever
  • Stomach cramps
  • Feeling dizzy or lightheaded

It may take hours or days to feel the effects of the bacteria from a cockroach. Drinking plenty of water is important to stay hydrated. Seek medical attention if you think you have food poisoning. Reporting it can help stop the spread, especially if it is linked to a specific location.

Can people be allergic to cockroaches?

Some people are allergic to cockroaches. Their waste and saliva can be allergens for some people. There is a protein in cockroaches that is an allergen. Cockroach allergies can cause an allergic reaction and also trigger asthma. An asthma attack can be deadly if not treated promptly. A rescue inhaler or immediate medical attention should be sought.

What happens if you get scratched by a cockroach?

If you get scratched by a cockroach it could get infected. Cockroaches have six-hairy legs and those legs can carry tiny bacteria. Remember how they like to hang out in city dumps and latrines? Well, that garbage stays on their legs, and if you try to handle one and accidentally get scratched, it is likely to get infected unless treated right away. Apply an antibacterial cream to any wound caused by a cockroach.

Do cockroaches live forever?

Can Cockroaches Fly - Cockroach on Bowl

Cockroaches do not live forever.


Cockroaches have a reputation for being difficult to kill and for surviving for generations. The early fossils of cockroaches look much the same as modern-day ones. They do seem to adapt well to new environments and reproduce efficiently, but cockroaches do not live forever. It depends on their species but the range is 4 months to a year. The American cockroach has an average lifespan of 12 months. Keeping your home clean and dry is the best way to keep these dangerous pests out of your home.

The photo featured at the top of this post is © gan chaonan/

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About the Author

I'm a Wildlife Conservation Author and Journalist, raising awareness about conservation by teaching others about the amazing animals we share the planet with. I graduated from the University of Minnesota-Morris with a degree in Elementary Education and I am a former teacher. When I am not writing I love going to my kids' soccer games, watching movies, taking on DIY projects and running with our giant Labradoodle "Tango".

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