13 Living Creatures Found on the Human Body

Crawling deer tick on human hairy skin background. Ixodes ricinus or scapularis. Dangerous parasitic mite on blurry pink texture. Disgusting biting insect. Encephalitis infection. Tick-borne diseases.
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Written by Sharon Parry

Published: May 15, 2024

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Even when you think you are alone, you are not! Less than half of the cells of your body are human with the rest being made up of tiny creatures who live on and in your body every second of the day. Each human body is a complex ecosystem that is completely unique. Some of these tiny creatures are on your skin whilst others are in your ears, up your nose, or in your intestines. Most are so tiny that you would need a microscope to see them but we don’t suggest you do that because some of them look quite scary!

Most of the time, these guys do not do us any harm. They feed on what our body has to offer and, in return, help our body function normally. As humans evolved, our ‘guests’ evolved with us. However, sometimes they reproduce to numbers that cause symptoms. Others, such as tapeworm, are parasites and do not help us at all! Let’s take a closer look at 13 living creatures on the human body.

Demodex (Face) Mites

Animals that don't poop – demodex mites

Demodex mites live on eyelashes and eye brows.


There are two types of Demodex mites living on the human body, Demodex folliculorum (D. folliculorum) and Demodex brevis (D. brevis) but you will never see them with the naked eye because they are just 1/64 inch long. Demodex folliculorum are the most common and are found on your nose, cheeks, chin, eyelashes, eyebrows, and scalp. Demodex brevis are more likely to also move to the neck and chest area. The majority of people have them but they usually don’t cause a problem. However, they may cause itchy, flaky skin in some people. These mites live off skin secretions but never poop!

Head Lice

You often spot head lice eggs rather than actual lice.


If you have had kids, you have probably had to do battle with head lice at some point. These pesky creatures live on human hair, eyebrows, and eyelashes. They feed several times a day by biting your scalp to reach your blood. This is what causes an allergic reaction and itching. Head lice do not jump – they crawl from one person’s head to another possibly via clothing or combs and towels. If one person gets head lice, the whole household must be treated with either prescription or over-the-counter medication.



You can catch ringworm from dogs.


You may be surprised to know that ringworm is not actually a worm – it is a fungus. The culprit lives on skin and on objects such as clothing and bedding. Ringworm on the feet is called ‘athlete’s foot’. It causes a red, itchy, circular rash and is passed directly from one person to another (possibly by sharing towels) but you can also get it from animals including dogs, cats, and horses. It is usually treated by an anti-fungal cream.


Scabies Infestation with secondary or superimposed bacterial infection in right hand of Southeast Asian, Burmese Child. A contagious skin condition caused by mites. Main symptom is intense itching.

Tiny mites in the skin cause scabies.

©Zay Nyi Nyi/Shutterstock.com

Scabies is a skin condition caused by Sarcoptes scabiei var. hominis which is a tiny mite. They burrow into the upper layer of the skin where they lay eggs. This causes itching and a rash. To get scabies from another person, you need prolonged skin-to-skin contact or sleep in the same bed. It is most common in institutions including university dorms. The treatment is with creams or lotions but you also need to wash all bedding and put clothing in a sealed bag.


White coating on tongue baby. Oral thrush.

A white coating on a baby’s tongue can be thrush.

©Victoria 1/Shutterstock.com

The fungus called Candida is found on most people’s bodies and usually causes no problems. The places it is found most often are the skin, inside the mouth, gut, and genitals. If it grows out of control or enters other parts of the body, it can cause itching and soreness. This is called thrush. If it gets in the bloodstream it can cause a fever.

Gut Microbiome

©iStock.com/Rasi Bhadramani

There is a complex ecosystem located inside your intestines. All of the organisms that live there together are called gut microbiota, gut microbiome, or gut flora. They include single-cell organisms, bacteria, viruses, and fungi – there are trillions of them! Far from causing us harm, these tiny creatures are vital for breaking potentially toxic food compounds and synthesising many nutrients. We each have out own unqiue biome – so we should look after it!

Pinworm (Threadworm)


Tiny pinworms can live in our intestines.

©Kateryna Kon/Shutterstock.com

Pinworms are small, thin, white roundworm called Enterobius vermicularis and are found most often in children and people living in institutions. They are about 0.05 inches long so you can just about see them with the human eye. They can cause itching around the bottom area. You can take oral medication to get rid of them but the whole family needs to be treated.


Tapeworm in intestine

Thankfully tapeworm are uncommon in the U.S.

©iStock.com/Artur Plawgo

As their name suggests, tapeworms are long and flat intestinal worms. They live in animals but some some species can live in humans including Taenia solium which you can get from pork. If you have tapeworm, you may suffer from nausea, diarrhea, and weakness but some people don’t even know they have them. They are uncommon in the U.S. thanks to animal hygiene practices.

Skin Bacteria

Our skin is home to countless bacteria.


Healthy skin is teeming with bacteria. The most common types are Staphylococcus, Corynebacterium and Propionibacterium. There are a million bacteria in just one square cm. All these tiny guests help to keep our skin healthy and functioning as it should.


Pubic louse (Pthirus pubis) under microscope

Sexual contact spreads public lice

©D. Kucharski K. Kucharska/Shutterstock.com

Human crabs, otherwise known as pubic lice (Pthirus pubis), are tiny insects that live in body hair, especially around the genitals. They are passed on through sexual contact. They can cause small red or blue spots on your skin. Treatment is medicated creams or shampoos.


Chiggers are the larval form of berry bugs.


These are tiny mites that are in the same family as ticks and spiders. They are found in all countries, often in fields and forests. When they bite to feed on your skin cells, it can make you itch and they attach to your skin for several days. Once they are full, they drop off!



The hookworm enters the body via the feet.

©Aut Pantian/Shutterstock.com

These worms were once common in the U.S. but cases are now rare. They live in the soil and penetrate the skin of the feet. From there, they travel to the intestines. Often they cause no symptoms but some people have blood loss leading to anemia.


Tick Header - Tick Burrowed In


Unlike many other harmless tiny creatures, ticks are an animal that you do not want to carry on your body. They are spider-like creatures that feed on the blood of mammals – including us. There are several tick species in the U.S. that can transmit several nasty diseases to humans. These include Lyme Disease and Tick-Borne Relapsing Fever. They are most active between April and September.

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About the Author

Dr Sharon Parry is a writer at A-Z animals where her primary focus is on dogs, animal behavior, and research. Sharon holds a PhD from Leeds University, UK which she earned in 1998 and has been working as a science writer for the last 15 years. A resident of Wales, UK, Sharon loves taking care of her spaniel named Dexter and hiking around coastlines and mountains.

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