The human body is a natural breeding ground for billions of creepy crawlers that most of us would normally wince at if we had a good look at them. Our heads, skin, and mouths are smorgasbords of sustenance that send microscopic animals into a feeding frenzy. Believe it or not, both incredibly small and astonishingly large organisms could be living on — and inside — your body at this very moment. And they're here to stay.
Microbiomes, as these human-dwelling creatures are called, can be anything from docile insects to harmful parasites. According to most scientists, including Katherine Harmon of Scientific American, microbiomes play an important role in the overall health of our bodies, organs, immune systems and other integral bodily functions. One example is the tiny microbes in stomachs and intestines. These little critters work tirelessly 24-hours a day, 7 days a week, to break down food and make it easier to digest. They also play a vital role in “crowding out” bacteria that is harmful to human health.
Research into the microbiome community is being characterized as “a new vista on biology.” After studies conducted by doctors such as Philip Tar and Bruce Birren, it has been found that "healthy humans carry a remarkable diversity of organisms.” For human beings, there is a unique population of microbial bacteria that reinforce the overall health of any given person. It’s good to know that most of the trillion species that make our bodies home are not always so bad. In fact, most are good. As is often the case with species in natural environments around the world, microorganisms and humans engage in an important symbiotic relationship: humans keeps microbes alive with food, and microbes keep humans healthy.
But that doesn’t mean that the thought of them crawling around our skin and swimming in our bodies isn’t off-putting. And that isn’t to say, either, that every single creepy crawler that can inhabit the body is altogether good for our health — in fact, some are fatal. The following list describes both types of microbiome, as well as much larger organisms that aren’t microbiomes at all. They are the good, the bad, and the very, very ugly of the microscopic world. Be warned, the following descriptions are not appropriate for readers with a sensitive stomach.
10 Dust Mites
Fortunately, most people aren't particularly aware of dust mites. Most of them are scavengers who live off the human body in areas where they will get plenty of food like dead skin or dead insects. Some types of mites, like the common house dust mite, can cause serious allergens when they come in contact with humans. Like a cockroach, their feces can become airborne, irritating people who are sensitive to their allergies. In addition, the itch mite, like its name suggests, can contact the skin and cause itching and rash.
9 Head Lice
Head lice are extremely common. As a kid, you may have picked them up at school,and you may even have had your entire head shaved to get rid of them. Today, they can be treated with specially medicated shampoos which are incredibly effective in killing them. Not only do they cause constant itching and skin irritation - they can carry thousands of diseases. Throughout history, they have been responsible for thousands of fatalities. Lice live and feed in and around hair follicles of all type - they crawl or hop instead of fly and are caught by close encounters with other infected beings, like cats, dogs, and other people.
8 Bed Bugs
As their name suggests, bed bugs are tiny insects (about the size of a louse) that often infest fabrics of any kind, including mattresses. Interestingly, bed bugs usually stay dormant until they sense a source of heat - such as a human body. When they wake, they attack the skin, bite, and cause severe itching and rashes. They feed themselves on animal fluids and can carry up to six times their own weight in blood. Look out for brown spots or an odd odour on your mattress. Although they do not necessarily live on the human body, they certainly love the taste. These are particularly creepy insects - people attacked by bed bugs have been known to suffer from Post Traumatic Stress Disorder.
7 Baby Squid
Yes, even baby squid can find their way into the human body, live and potentially grow there. One of the most bizarre cases of baby squid entering a human is reported by The Daily Mail. After eating calamari, a 63-year old woman felt a painful sensation in her mouth. When she had her mouth examined by a doctor, she found that 12 baby cephalopods were attached to the inside. There is no telling with any certainty how long the baby squid could have lived in her mouth if it was untreated, but, given the right circumstances, they could have fed and matured. The doctors were able to successfully remove the squid's sperm sacs.
6 6. Tapeworms
Tapeworms, also known as parasitic flatworms, are one of the most well known of the parasites. Some women have even been known to purposefully infect themselves with tapeworms to effectively lose weight. Unfortunately, it can be quite easy for humans to become infected with tapeworms if they eat raw or undercooked beef or pork. They often make their home inside the digestive tracts of animals, including humans, and can grow to an astonishing 15 meters (50 feet) in length while devouring the vessel's food. One form of treatment to rid oneself of the parasite is by taking special medication which allows one to, ahem, eject the tapeworm from the body and flush it down the toilet.
5 Guinea Worm
This parasitic worm found in the Amazon infects humans when they drink water containing copepods. When those little crustaceans make their way into the stomach, they eventually die and release larvae that infect the abdominal wall and other parts of the stomach. The larvae soon develop into adult worms that feed on anything they can find. After the females make their way up to the skin and contact water, they release the larvae to infect another batch of copepods. Although the guinea worm isn't supposed to infect humans, in this case they don't leave human body until their breeding cycle is complete.
This parasite can live in a human being for up to 20 years. According to Stanford University, humans can become infected by the parasite when eating raw or undercooked pork. The parasite can cause a great deal of pain when the larvae dies under the skin. As the spargana develops through various stages in the human body, it can damage surrounding organs. In other words, the spargana can be lethal to humans if never treated. The only way to treat an infected person is by surgically removing the parasite from areas including the skin and even the brain.
Candiru is not a microbiome. Rather, it's a type of parasitic catfish found in the Amazonian rain forest. The smaller species of this parasite do not enter the human body through the eyes, mouth, or skin like many other critters — they enter the body through the urethra. The first documented case of this happening was in 1997. While standing thigh-deep in a river and urinating, the candiru made its way up a person's urethra. The fish was removed after a two-hour surgery. According to biologist D Scott Smith, the candiru had tiny spikes to make it easier to cling to its host.
2 Triatomine Bugs
The triatomine bug isn't some exotic insect found in some remote corner of the world. According to Centers for Disease Control and Prevention, the bug is common in the Southern United States, Central and South America. They usually live under porches or between cracks of old houses. The bugs often contain a parasite that can enter the bloodstream of humans and cause Chagas disease. Although the bug itself doesn't live inside the body, the parasite - Trypanosoma cruzi - most certainly does. However, you might be thankful to know that in the United States chances of contracting the disease through the bug are very low, even if it is infected with the parasite.
Maggots. The mere sound of the word is enough to make even the bravest squirm. And that’s just what maggots do: squirm, burrow and, yes, eat human flesh. An interesting and stomach-churning case of maggots living inside a human was reported in The Daily Mail. Catherine Stewart, a British woman doing work in Gambia, Africa, returned home one day and noticed red bites on her stomach. After one of the bites turned yellow, she squeezed it and felt something squirm under her skin. With the help of her husband, she pulled out not one, but six, maggots who were put there by the tumbu fly.