Just in time for holiday cookie season, we’ve discovered that the vanilla flavoring in your baked goods and candy could come from the anal excretions of beavers. 
 
 Beaver butts secrete a goo called castoreum, which the animals use to mark their territory. The U.S. Food and Drug Administration lists castoreum as a “generally regarded as safe” additive, and manufacturers have been using it extensively in perfumes and foods for at least 80 years, according to a 2007 study in the International Journal of Toxicology. 
 
 “I lift up the animal’s tail,” said Joanne Crawford, a wildlife ecologist at Southern Illinois University, “and I’m like, ‘Get down there, and stick your nose near its bum.’” 
 
 “People think I’m nuts,” she added. “I tell them, ‘Oh, but it’s beavers; it smells really good.’” 
 
 Castoreum is a chemical compound that mostly comes from a beaver’s castor sacs, which are located between the pelvis and the base of the tail. Because of its close proximity to the anal glands, castoreum is often a combination of castor gland secretions, anal gland secretions, and urine. 
 
 The fragrant, brown slime is about the consistency of molasses, though not quite as thick, Crawford said. 
 
 While most anal secretions stink—due to odor-producing bacteria in the gut—this chemical compound is a product of the beaver’s unique diet of leaves and bark, Crawford added. 
 
 Instead of smelling icky, castoreum has a musky, vanilla scent, which is why food scientists like to incorporate it in recipes. 
 
 Save a Cow, Milk a Beaver 
 
 But getting a beaver to produce castoreum for purposes of food processing is tough. Foodies bent on acquiring some of the sticky stuff have to anesthetize the animal and then “milk” its nether regions. (Read about scientists who milk mice.) 
 
 “You can milk the anal glands so you can extract the fluid,” Crawford said. “You can squirt [castoreum] out. It’s pretty gross.” 
 
 Due to such unpleasantness for both parties, castoreum consumption is rather small—only about 292 pounds (132 kilograms) yearly. That statistic includes castoreum, castoreum extract, and castoreum liquid, according to Fenaroli’s Handbook of Flavor Ingredients. 
 
 Still concerned you’re chowing down on beaver-bum goop? Because of its FDA label, in some cases, manufacturers don’t have to list castoreum on the ingredient list and may instead refer to it as “natural flavoring.” Yum. 
 
 Follow Mollie Bloudoff-Indelicato on Twitter. ||||| Andrew Unangst/Photographer's Choice/Getty Images 
 
 As any Cosmo reader will tell you, it’s a well-tested truth that men love the smell of vanilla. Turns out though, that men may not be falling for a scent that reminds them of childhood, but for something else entirely: Castoreum a.ka. a fragrant, brown slime that comes from a beaver’s castor sacs, which are located pretty much where you expect them to be located. 
 
 The chemical compound that beavers use to mark their territory has a musky, vanilla scent, which is why some perfume makers incorporate the component into their products and food scientists add the all-natural ingredient into recipes. As one can surmise, the vanilla aroma is not typical of the area, but is a product of the beaver’s unique diet of leaves and bark, said Joanne Crawford, a wildlife ecologist at Southern Illinois University, speaking to National Geographic. 
 
 Collecting castoreum can be a tricky endeavor though. A beaver’s castor sacs are located between the pelvis and the base of the tail. Because of its close proximity to the anal glands, castoreum is often a combination of castor gland secretions, anal gland secretions, and urine. “You can milk the anal glands so you can extract the fluid,” Crawford said. “You can squirt [castoreum] out. It’s pretty gross.” That may explain why castoreum is not an especially common source of vanilla flavoring. According to Fenaroli’s Handbook of Flavor Ingredients, published in 2005, total annual consumption of both castoreum extract and castoreum liquid was around 250 pounds, undoubtedly because the milking process is unpleasant for all parties involved. 
 
 The U.S. Food and Drug Administration lists castoreum as a “generally regarded as safe” additive, and manufacturers have been using it extensively in perfumes and foods for at least 80 years, according to National Geographic and a study in the International Journal of Toxicology. Because the FDA considers the ingredient safe, in some cases, manufacturers don’t have to list castoreum on the ingredient list and may instead refer to it simply as “natural flavoring.” Apparently “gross” is not something the FDA quantifies. 
 
 MORE: The Web Hates Burger King’s Fake Name Change 
 
 MORE: Child’s Birthday Cake Attacked In Washington Courthouse
– Like vanilla ice cream? Don't read this—because the smell of a beaver's butt is key to at least some vanilla flavoring, Time reports. More specifically, beavers like to mark their territory with a musky, vanilla compound located in sacs between the pelvis and the base of the tail. Manufacturers have been extracting it for 80 years to flavor foods and perfumes—but it's tricky, because the compound often mixes with urine and anal gland secretions. "You can milk the anal glands so you can extract the fluid," wildlife ecologist Joanne Crawford tells National Geographic. "You can squirt it out. It’s pretty gross." But she admits to sticking her nose in there and taking a whiff: "People think I’m nuts. I tell them, 'Oh, but it’s beavers; it smells really good.'" For the record, the slimey brown compound is extracted by anesthetizing a beaver and "milking" its nether regions. Ice cream sundae, anyone?