Often criticized for being an inconvenient, odorous consequence of digestion, poop may be the most abundant natural resource in the world. Take a look at 15 ways people are successfully turning feces into profits.

1. Become a Poop Donor.

Under normal circumstances, ingesting poop would be a sign of mental illness. In certain cases, however, it can grant relief to patients overcome with the C. difficile bacteria. “C. diff,” which is often acquired in hospitals, results in a serious gastrointestinal infection. Recently, a company called OpenBiome has been supplying physicians with fecal samples from healthy subjects that can restore a normal bacterial balance in the gut when taken via endoscopic induction or capsule. Medically screened donors can earn $40 a day, with a $50 bonus for coming in several times a week to make a defecation deposit at OpenBiome’s Medford, Massachusetts office. That’s over $13,000 a year just to poop under medical supervision.

2. Offer to Mail Poop to an Enemy.

While the United States Postal Service takes liquids and perishables seriously, they rarely ask if your package contains fecal matter. Because it’s not exactly illegal to mail poop, several services have cropped up in recent years that offer to send cow, bull, and other animal feces to recipients. Unless a court can prove the sender intended to harass the addressee—as opposed to merely perpetuating a practical joke—there aren’t many consequences. But if law enforcement does get involved, sites like PoopSenders won’t hesitate to turn your information over to the poo police.

3. Re-Design the Poop Experience.

Squatty Potty

Did you know that you may be pooping incorrectly? Robert Edwards, the inventor of the Squatty Potty, theorizes that humans should eliminate like cavemen (and much of Asia and the Middle East) used to: by squatting down, knees up, to reduce pressure on the rectum. The Squatty Potty is little more than a stepstool that sits near the toilet, but its health claims have turned it into the toilet version of buying organic. Edwards has seen his business flourish after mentions on Shark Tank and The Howard Stern Show. Fancy poopers can enjoy a bamboo version; the inflatable variety (above) can be packed into suitcases for going on the go.

4. Heat Buildings Using Poop.

Greenhouses require high temperatures, which can affect one’s utility bill. But if you have access to horse manure, your property can become a self-sufficient operation. Eagle Creek Wholesale in Ohio, for example, uses a mixture of horse poo and sawdust to heat enclosed areas. The poop fuel is burned at temperatures of up to 660 degrees.

5. Start a Pooper Scooper Business.

DoodyCalls

Domestic dogs and cats have been proven to ease owner stress, but having to clean up after them can foul the mood. Several companies are profiting by offering to take up this unpleasant task: DoodyCalls takes care of both lawns and litter boxes. Customers pay $15 to $35 for weekly services. DoodyCalls claims to be “No. 1 in the No. 2 business,” but Tennessee competitor Tidy Paws might have also have a valid claim to the porcelain throne: they gross over $170,000 a year.

6. Start a Cloth Diaper Service.

While Pampers, Huggies, and other disposable diapers remain a billion-dollar business, some new parents prefer the eco-friendly cloth alternative. (Some proponents even claim cotton is healthier for a baby than synthetic and chemical materials.) For those looking to have their infant poop old-school, diaper services can provide special hampers for dirty deposits and even no-pin diapers to avoid accidentally sticking your little one. Worried about the smell? Hospital-grade pail liners are used, and one service advises parents to “shake out any big solids” before disposal.

7. Identify Poop Vandals.

No one likes to step in animal waste—especially if it’s been recklessly deposited on your property. If the problem isn’t going away and you happen to live in an apartment complex, Poo Prints can help: laboratory workers have cheek swabs on file from every residential animal, giving them a DNA database that they compare to the unclaimed poo to identify the furry culprit. If an owner fails to clean up after his or her pet, the property manager can impose a fine.

8. Create Poop Art.

In the boundary-pushing work of fine art, no subject—or artistic instrument—is taboo. In 2013, the Public Works gallery in San Francisco mounted an exhibition featuring works composed almost entirely of animal feces. Images of Che Guevara, world maps (as seen above), and pop culture icons were all part of the turd collage. But with prices up to $3,500, making the first poo Rothko a part of your personal collection could be an expensive proposition.

9. Make Rabbit Poop Tea.

Rabbit breeders are big proponents of what they call “bunny berries,” the highly convenient and pellet-sized waste products of their animals. The low-odor pellets break down easily in potting soil; one can also steep the feces in water, creating a “tea” that can be used as a fertilizing spray for gardeners.

10. Power a Poop Bus.

Soaring fuel prices have compelled some bigger thinkers to experiment with alternative energy sources. UK’s “Bio Bus” is propelled by biomethane gas, which was obtained from sewage facilities and then processed. Bristol has plans to induct the bus into its regular public fleet and charge fares. A full tank of gas can take the vehicle 300 kilometers, or about 186 miles.

11. Peddle Poop Jewelry.

The Winking Moose

We all have someone notoriously difficult to buy for come holidays or birthdays. Why not gift them with an ornamental turd? That’s the idea behind the Winking Moose, an Alaskan trinket company that takes moose poop, coats it in polyurethane, and decorates it for wear as an earring, necklace, or tree ornament.

12. Make Bricks From Cow Dung.

Have you ever considered the durability of cow poop? Most of us have, but few are willing to capitalize on it. One company in Indonesia has proposed using cow dung to fabricate bricks that are subsequently piled up for construction projects. Purported to be 20 percent stronger than clay, the dung could one day redefine what it means for a home to be green.

13. Solve the Problem of Dogs Eating Their Poop.

Known as coprophagia, the desire for dogs to eat feces can make it hard for humans to fully relate to their canine companions. Some companies have addressed this by offering tablets or pills that discourage animals from snacking on poops by making them taste bad. (This introduces the premise that their poop was delicious before, but it’s best not to dwell on these things.)

14. Make Poo Paper.

PooPooPaper

Some animals have a hard time breaking down certain fibers, resulting in a rather pulpy poop. Enterprising minds in Thailand and other locations take the coarse strands from the excrement, process it, and use it to manufacture a variety of stationery products. One company, PooPooPaper, claims “brown is the new green” and has a “Pootique” with journals, gift cards, and note pads.

15. Harvest Rare Whale Poop.

Among the many rare specimens to be found in the world, the intestinal discharge of a sperm whale is among the most valuable. Called ambergris, the mineral-like substance (hard, waxy, shiny) is treasured by beachcombers as a kind of poop Hope Diamond. Used in some fine cuisine and perfumes, just a pound of ambergris can net its excavator $10,000 or more. A couple in South Australia happened upon 32 pounds of the stuff, netting them a $300,000 profit.