We're sorry in advance if we've just ruined your appetite.
For the past 80 years, we've been using the "brown slime" emitted from beavers as a way to add vanilla, strawberry and raspberry flavors to some of our favorite foods.
How exactly does this work? Beavers emit the chemical compound castoreum from their castor sacs. The sacs are located under the animal's tail and are secreted when they seek to communicate or mark their territory.
And because of this location, "castoreum is often a combination of castor gland secretions, anal gland secretions, and urine." National Geographic describes it as a "musky, vanilla scent", making the secretions a go-to for some food scientists and even perfume manufacturers.
In case you were curious, it's not just the beaver's secretions that smell good -- but their butts, too! "I lift up the animal's tail and I'm like, 'Get down there, and stick your nose near its bum,'" said wildlife ecologist Joanne Crawford to National Geographic -- though we think we might be keeping our distance.
Related: Wildest ice cream flavors ever