Do you have a nagging, gnawing feeling that …well, just a nagging, gnawing feeling? You should-odds are you’re being slowly devoured by one of these tiny, vicious parasites right this very second.


BIO: Fleas are tiny insects that just can’t live without blood. They eat more than 15 times their body weight in blood in a single day. That includes the blood of dogs, cats, rats, rabbits, and any other mammal that’s handy, including you. They’re also “Super Bugs”: Fleas can pull 160,000 times their own weight (the equivalent of a human pulling 24 million pounds) and can jump over 150 times their own size (the equivalent of a human jumping about 1,000 feet).

DANGER! In the right-or wrong-conditions, fleas are disease machines. They can transmit tapeworm to pets or humans, and can carry a number of diseases, including the blood parasite babesia, and the dreaded bubonic plague.Thankfully, they’re not nearly as bad as they were in the days before the vacuum cleaner. (Most eggs hatch in your carpet.) Image credit: Flickr user Dr. Hemmert.

EATIN’ YOU: Bedbugs

BIO: Tiny, painful, smelly, and disgusting, bedbugs are nocturnal, spending the day in walls, furniture, or in your bed. At night they crawl out of the mattress and suck your blood. And they can wait up to a year in that mattress between feedings.

DANGER! Their bites are often painful, but, thankfully, bedbugs are not known to transmit any diseases. Image credit: Flickr user PeterEdin (Tag Man).


BIO: Ticks are arachnids-not insects-and are related to spiders. There are no ticks that live solely on humans, but if there are no deer, cattle, birdsd, or reptiles handy, you’ll do. They have three life stages after hatching-larva, pupa, and adult-and each stage needs a “blood meal” before morphing into the next stage. Ticks use a hunting technique known as “questing”. That means that since they can’t hop or fly or run after prey, they wait around on grass or twigs for a host to come to them. How long will they wait? Years, possibly decades. And despite all that sitting they can leap into action the instant they sense a host coming by. One female tick can increase its body weight 200 times in a six-day feeding. Human equivalent: going from 170 pounds to 34,000 pounds in a week.

DANGER! Only mosquitoes transmit more diseases to humans than ticks do. Image credit: Flickr user Micah Taylor.

EATIN’ YOU: Chiggers

BIO: Chiggers are the blood-sucking, infant larva of mites, but before they can grow up, they must eat. They prefer rodents and lizards, but they’ll happily dine on you. These ravenous babies digest skin cells by spitting up powerful enzymes. Irritated skin cells react by building a hard mound around the tiny hole created by the enzymes, forming a “straw” (called astylostome) through which the chigger continues to suck your mushed skin.

DANGER! Chigger bites are possibly the most irritating and itchy bites in the world-and the sores can itch for weeks-but they’re not known to carry any diseases. Old wives’ tale: Putting nail polish over the hole will suffocate the submerged parasite. Wrong! Chigger do not burrow underneath the skin. If you have sores, you probably already scratched the chiggers off. Image credit: Flickr user Cabezalana.

EATIN’ YOU: Face mites

BIO: What’s that on your eyelid? It might be one of those microscopic mites. They live in the pores and the hair follicles of the face, especially around the nose and eyelashes. They plant themselves head-down on a pore or follicle, and happily live there feeding on sebaceous secretions and dead skin debris.

DANGER! Usually you wouldn’t notice them, but bad infestations can cause the face to become polluted by the excrement and and corpses of these invisible bugs. That and their eating of hair roots and oil glands may cause hair loss, rashes, and rough skin. They are not known to transmit diseases.

EATIN’ YOU: Head lice

BIO: These bloodsuckers live their entire lives on the human scalp and hair. They puncture your skin with special piercing/sucking mouthparts and feed two to six times a day. They’re particularly prevalent among children, who can spread them easily by sharing hats and combs, and by playing games such as “I’m gonna rub my lice-infested head against your head …because its fun!” (But personal hygiene is irrelevant-they’ll live on anybody.)

DANGER! The bites may itch, but head lice aren’t dangerous. Image credit: Flickr userEran Finkle.

EATIN’ YOU: Crab lice

BIO: Also permanent human residents, these larger lice live in the warmer, moister climes of pubic and armpit hair. They’re sluggish: If not disturbed, one can live its entire life within a half-inch of where it was born, but, like all lice, can be passed to other people through close contact. Not gross enough? Crab lice can also live in beards, moustaches, eyebrows, and eyelashes.

DANGER! Like head lice, you’re only in danger of embarrassment from crab lice.

EATIN’ YOU: Human liver fluke

BIO: This flatworm is contracted from eating infected fish, and primarily targets humans. They live in your bile ducts and liver tissue, as well as blood, and can grow up to an inch long and can live inside you for ten years.

DANGER! Symptoms can range from none …to death, for heavy infestations. (There have been cases where one person housed more than 20,000 of the parasites.) They are most prevalent in Asia, where raw and pickled fish are dietary staples. Image credit: Wikimedia user Flukeman.

EATIN’ YOU: Mosquitos

BIO: Contrary to popular myth, mosquitoes do not live on blood. They survive on nectar and other fluids sucked out of flowers. But females take a “blood meal”-they need protein to develop their eggs. You can’t hide: Mosquitos home in on their prey using specialized organs that can sense heat, carbon dioxide-which you just exhaled-and other gasses from up to 100 feet away.

DANGER! Mosquitoes traveling between hosts can transmit several diseases to humans, including malaria, sleeping sickness, and elephantiasis. Mosquitoes are the most deadly animal to humans on earth, causing more than 1,000,000 deaths a year.Image credit: Flickr user bogdog Dan.