Humans and other animals ooze and excrete valuable substances that are worth a pretty penny on the open market. There's a very specific going rate for much of what's inside us (especially the gross stuff). If you're thinking about getting in on the bodily fluid trade, here are 11 icky substances expelled by living things that are worth some serious cash.

1. Guano, Seabird, and Bat Poop

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You don't have to be Ace Ventura to know that the feces of seabirds and bats makes for great fertilizer. The demand for guano is high and the industry is once again thriving, but the smelly commodity is not mined with the same fervor that it was in the late 1800s, when the multimillion-dollar poop trade inspired diplomatic disputes and proxy wars throughout the Pacific islands and South America.

2. Ambergris (Whale Poop/Vomit)

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Ambergris is a bile substance that is digested and excreted or coughed up by sperm whales. It hardens in the ocean and occasionally washes ashore, looking like a large stone. Freshly pooped or spewed, ambergris has an intensely foul odor. But after a careful aging process, the hardened vomit takes on a sweet, earthy scent—highly prized in the fragrance business for its use in colognes and perfumes. Finding a couple pounds of ambergris on the beach is nearly as good as happening upon several thousand dollars in hard cash.

3. Toddy Cat Coffee Bean Droppings

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When the Asian palm civet, or Toddy cat, eats scavenged coffee beans during harvest season, it deposits (poops) them out the other end of its digestive tract with the outer shell removed and the beans' flavors somehow enhanced. Ground up, the bean droppings make a cup of joe worth anywhere from $8 to $30. Caffeine aficionados swear by the stuff.

4. Human Eggs and Sperm

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This one is no surprise, but the reverse gender wage gap is interesting. While men's sperm typically fetches somewhere between $50 and $200, in 2010, a woman could earn upwards of $5000 for donating a portion of her more finite supply of eggs.

5. Human Plasma

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Most people give their blood away for free. Suckers! The part of your blood that fills it with proteins that help it clot—the plasma—can make you $300 a month.

6. Human Hair

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My friend once tossed his wet, recently shaved hair through the open window of a college sorority's bathroom. All he got was dirty looks and vengeful rumors. He should have sold his hair to wig makers, who actually pay for the locks.

7. Bird Spit

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About 400 years ago, someone in China saw white nest cliff swifts building nests out of their saliva along the high sea walls of the coast and thought, "wow, that would make a great soup." The delicacy has been incorporated into various Chinese dishes ever since. A pound of the stuff is worth more than $1000.

8. Scorpion Venom

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Scorpion venom can leave you writhing in pain, or even dead. It can also land you several thousands of dollars. It's highly prized because protein in the venom can be used to make drugs for conditions like rheumatoid arthritis, inflammatory bowel disease, and multiple sclerosis.

9. Elephant dung coffee

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Like the Toddy cat coffee of Indonesia, the coffee made with beans digested by elephants in Thailand is apparently dark, smooth, and expensive. After a slow, slow roast in the digestive tract of Asian elephants, the coffee beans are ground, brewed, poured into a mug, and sold for $50.

10. Silk

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James and his giant peach weren't in it for the adventure, they were in it for the silk and the cash. Even with the advent of synthetics, real silk remains coveted by the fashion world, making silk worm farming fairly profitable.

11. Castoreum (Beaver Butt Secretion)

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Castoreum is the fluid extracted from the castor sacs, or scent glands, of beavers. The sacs are located right between the base of a beaver's tail and its anal glands. Though castoreum is produced in limited amounts (you can imagine why), it is sellable, as it has a rather pleasant smell and is used in some perfumes (and also as a food additive).