Next time you pick up a vanilla candy, think twice. A chemical compound used in vanilla flavored foods and scents, castoreum, comes from the butt of a beaver.
Castoreum comes from a beaver's castor sacs, located between the pelvis and base of the tail. Due to its proximity to the anal glands, the slimy brown substance is often mixed with gland secretions and urine.
Manufacture have been using castoreum as an additive in foods and perfumes for at least 80 years, according to a 2007 study in the International Journal of Toxicology.
And the worst part? The FDA-approved castoreum is not required to be listed as an ingredient on food items. Manufacturers may list "natural flavoring" instead.