We all know about the nice things that live inside us, like love and friendship and hope, but what about the grizzly stuff with claws and pupae? Eww ... pupae.

If you're both morbidly curious and intensely squeamish, it's time for these two facets of your personality to battle to the death by checking out this collection of eight of the shiver-inducingly gross animals and parasites that can live inside you.

Warning: This list may make you itch.

Creature: Hookworm
Found in: Mainly the intestines, but also in the heart or lungs
What does it do? Generally, hookworms burrow into the human body using an enzyme that dissolves layers of skin. Once they're in your bloodstream, they travel around your body and suck blood wherever they can -- though they are generally found on the walls of the large intestine. If you're lucky, they'll end up perishing in your strong stomach acid.
How do you know if it's inside you? Your feet are itchy, and your cat is scratching its ass on stuff.

Creature: Scabies
Found in: Your skin
What does it do? Female scabies mites are attracted to warm, moist skin. Not only that, they burrow down into it, gorging on your dermis as they go. There their eggs hatch, and the mites return to the surface to find other mites to mate with, who, once they've done it on your skin, burrow into you again. The filthy beasts. To them, you're essentially Amsterdam.
How do you know if it's inside you? You have an itchy red rash and have become a hotbed for illicit fornication.

Creature: Schistosoma
Found in: Usually it resides near the liver, though there have been cases when it has attacked the brain.
What does it do? Schistosomiasis (or "snail fever") is one of the most common parasitic infections in the world. The parasite, which typically travels in unlcean water, usually enters in the human body through the skin and takes many months to manifest any symptoms.
How do you know if it's inside you? You have abdominal pain, a cough and genital sores.

Creature: Candiru
Found in: Your willy. Yep. This is the Amazon willy fish that often comes up in conversation.
What does it do? The candiru generally skulks about in the waters of the Amazon waiting to slip into the gills of passing catfish, using its spined head to hook itself in before sucking on its host's blood. The candiru is guided by the smell of urine, and the human brand is too delicious for it to miss out on. Now we don't know about you, but the thought of spiny-headed fish swimming anywhere near that area is essentially our worst nightmare.
How do you know if it's inside you? Do you feel like you've got a spiny-headed fish in your willy?

Creature: Jiggers, chiggers or chigoe flea
Found in: Your feet
What does it do? This little dude is the cousin of the swine-flea that spread the bubonic plague. It can jump eight inches and burrows into the feet of its hosts, generally between the toenail and toe. Once there, it swells and lays dozens of eggs, each of which will mature to a full-grown flea within 3 to 4 weeks. Infections cause swelling and serious itching.
How do you know if it's inside you? Got one of the those (see left) on you?

Creature: W. Bancrofti
Found in: The lymphatic system
What does it do? These 3- to 4-inch worms usually enter the body through bites made by mosquitoes that contain their larvae. They travel to the lymphatic system where they breed and grow and eventually cause a variety of genuinely awful diseases, including elephantitis.
How do you know if it's inside you? First clue is usually a weird yellow mucus secretion from your legs, followed by swelling around your family jewels, which can happen years later.

Creature: Tyrannobdella rex, or tyrant leech
Found in: Your nose
What does it do? Well, it's a leech, so what do you think it does? This gross, little monster has teeth the width of a human hair, which is gigantic by leech standards. And it uses its single jaw in a sawing action to break into the flesh to suckle on its number one nectar of choice: your ambrosial blood.
How do you know if it's inside you? A sliding sensation in the nose

Creature: Human Botfly
Found in: Your skin
What does it do? This creep hijacks mosquitoes and infects them with its larvae, which are then injected, via mosquito bite, into the skin of an unsuspecting host. The eggs eventually hatch and form into pupae that fall out of the skin and turn into botflys. Want to see how big they are? Watch the video below (if you can stomach it).
How do you know if it's inside you? Because it looks something like this: