Yes, it's true. You may be eating sex gland excrement from a Beaver’s butt! Millions of people across the globe are eating "beaver butt". It's called "castoreum". Beavers eject this slimy brown substance to mark its territory, but for us humans, it's used as an additive that is often labeled as "natural flavoring" in the foods we eat - vanilla, strawberry, raspberry probably the most common. From perfumes to air fresheners, castor sacs are quite versatile within the fragrance industry.