Creepy Crawlies: 7 more little things that make life special

In case yesterday's story on horrifying parasites didn't leave you sufficiently creeped out, Chris Weber is here to tell you about seven more creepy crawlies. Afterwards, have a look at our own Ransom Riggs' latest original video: Attack of the Killer Parasites.

Remember that scene in Star Trek: The Wrath of Khan when Ricardo Montalban drops a weird-scorpion spacebug into a poor guy's ear? That was fiction; these suckers are real. Here are seven parasites, ranging from common to obscure, that will make your sphincter clench with fear.

1. Pinworms Pinworms look like little pieces of uncooked spaghetti in your poop. They're quite common: One out of three children will have them. Kids pick up the larvae while digging in the dirt, and as soon as they put their fingers in their mouths, it's home free! It matures in your intestine and then, in a miraculous moment worthy of Nova, Momma Pinworm slithers out of her host's anus in the middle of the night and lays her eggs on the surrounding skin. Having a family of pinworms camped around your butthole itches, and so people respond by scratching like hell. In the process, they get pinworm eggs under their fingernails, and the circle of life goes on.

2. Ascaris lumbricoides

Ascaris lumbricoides is one of the largest parasites to infect humans. About a quarter of the world's population carries around this roundworm, which can grow to be as thick as a pencil and as long as two or three. Ascaris hangs in your small intestine, where it eats food passing through. A female Ascaris can fill up said intestine by laying around 300,000 eggs a day. Those babies have to go somewhere, and that's when the trouble really begins, as one expert described: "Ascaris has a tendency to wander places it shouldn't. If the conditions start to become unfavourable (e.g., the host gets a fever, undergoes anaesthetic or takes worming tablets), the worms will try to get away. If they wander down the intestine, they may be passed with the stool (giving one an awful fright the next time one goes to the toilet), they may wander back up through the stomach and be vomited up (there have been cases of the worms suffocating infants by climbing up behind the nasal passages) . . ."

3. Plasmodium No list of human parasites would be complete without plasmodium, the protozoa that causes malaria, which originally earned the nickname "jungle fever." Transmitted through the bite of the Anopheles mosquito, plasmodium takes up residence in your liver within 40 minutes. There it reproduces inside your cells. If enough of these cells burst at one time, your fever spikes. From the liver, the plasmodia can invade other organs like the spleen, kidneys, and brain. As many as 500 million people a year contract malaria, with a particularly heavy toll among children.

4. Lice

Lice come in several hundred varieties, three of which use the human body as a condominium: body, head, and pubic lice. Their preferred food is warm human blood. Eggs and baby lice are called "nits," hence the expression "nit-picking." Head lice can spread to the eyebrows, eyelashes, and beard. Their primary symptom is intense itching triggered by lice saliva. The other sign you may have crabs is brown spots in your underwear: lice droppings. Unfortunately, good hygiene can't protect you; you can win a grooming award and still have lice. "If you don't like doing laundry," one mother of three told me, "you'll be sad to have lice come into your home." In some upscale communities, salons offer a lice package so kids can get treated without having to feel the stigma of their peers' ridicule.

5. Trichinella You can get the worm Trichinella by eating raw or undercooked pork—or bear, fox, horse, seal or walrus. However, as one insightful Stanford student pointed out, "you CANNOT spread trichinosis to others (unless they eat you)."

6. Amoebas

Amoebas are cute when they're swimming around on your microscope slide, but they can wreak havoc inside you. One illness caused by amoebas, amebiasis, is transmitted via contaminated food or anal sex. Amebiasis is very common; it kills more people than any other parasite besides the malaria plasmodium. The much rarer amebic meningoencephalitis involves amoebas eating your brain. Ninety-five percent of people with this condition die.

7. Hookworms Hookworms are shaped like rough hooks, with bent heads that latch on to the inner wall of your intestine. Like lice, they suck your blood. Remember Jeff Foxworthy's jokes about the chronic laziness of rednecks? Well, the propensity of some rural Southerners for lying around was probably due, at least in part, to their hookworm problems. You're not going to feel like doing much work with several thousand worms inside your gut.

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Chris Weber is an occasional contributor to mentalfloss.com.