Bearcats smell like popcorn because their urine contains the same chemical compound that gives freshly popped popcorn its buttery, roasted aroma. The compound is called 2-acetyl-1-pyrroline, or 2-AP, and it shows up in every bearcat tested. It’s one of those strange overlaps between animal biology and food chemistry that sounds made up but is well documented.
What Bearcats Actually Are
Despite the name, bearcats are neither bears nor cats. Their proper name is binturong, and they belong to the civet family (Viverridae), a group of small to mid-sized carnivores found across Southeast Asia. Binturongs are one of the largest members of that family, with stocky bodies, short legs, thick black fur, and a prehensile tail nearly as long as their torso. Adults weigh around 20 kilograms (44 pounds). Females are actually larger than males, which is unusual among carnivores.
They spend most of their time in trees, gripping branches with that muscular tail. The “bearcat” nickname comes from their appearance: a bear-like body paired with a cat-like face, complete with short muzzles and long white whiskers.
The Exact Chemical Behind the Smell
The popcorn scent comes from 2-AP, a molecule normally created through high-heat cooking reactions. When you pop corn kernels, the sugars and amino acids in the kernel undergo a series of chemical changes called the Maillard reaction, producing 2-AP as a byproduct. That’s what fills your kitchen with that unmistakable smell.
Binturongs produce the same molecule in their urine, but without any heat. A 2016 study from Duke University analyzed volatile compounds in binturong urine and found 2-AP in every single animal sampled. The mystery is how: the Maillard reaction typically requires temperatures well above what a living body produces. Researchers believe some combination of hormonal activity and complex chemical reactions in the animal’s body generates 2-AP through a different pathway, but the exact mechanism hasn’t been fully pinned down yet.
How Binturongs Spread the Scent
Binturongs don’t just happen to smell like popcorn. They actively use the scent as a communication tool. Both males and females urinate in a squatting position, deliberately soaking their feet and their long tails. As they walk and drag their tails along branches afterward, they leave a scent trail through the canopy.
This trail serves two purposes: marking territory and advertising to potential mates. Other binturongs encountering the trail can pick up information about who left it and, likely, whether that animal is ready to breed.
Binturongs also have paired scent glands located on either side of the anus, which they use for additional scent marking. But the secretions from those glands are mostly short-chain fatty acids. They contribute to the animal’s overall odor profile, but they aren’t what produces the popcorn smell. That comes specifically from the urine.
Males Smell More Like Popcorn Than Females
Not all binturongs smell equally buttery. The Duke study found that males produce significantly more 2-AP in their urine than females do. The amount of 2-AP was directly tied to levels of androstenedione, a hormone involved in producing both testosterone and estrogen. Animals with higher androstenedione had stronger popcorn scent, regardless of sex.
This hormonal link suggests the scent carries real biological information. A binturong sniffing a scent trail could potentially assess the sex of the animal that left it and gauge its reproductive condition, all from the strength and chemical signature of the urine. In a species where individuals are spread across dense forest canopy and may rarely see each other face to face, that kind of chemical messaging is invaluable.
Why This Is So Unusual
Plenty of animals communicate through scent. What makes the binturong remarkable is that its signature compound is one we associate entirely with cooked food. 2-AP shows up in popcorn, white bread crust, jasmine rice, and tortillas. In every other known case, producing it requires heat. The binturong is the only animal known to generate significant quantities of 2-AP biologically, at normal body temperature, through a process scientists still don’t completely understand.
If you ever visit a zoo that houses binturongs, you can confirm the smell yourself. Zookeepers frequently describe the enclosures as smelling like a movie theater. The scent is strong enough to notice from several feet away, and it lingers on surfaces the animals have touched.