Only two mammals like spicy food: humans and the tree shrew.

While humans have long had the rare distinction of being the only mammal that actually enjoys spicy food, that list has seen a new addition, as a study by Chinese researchers found that tree shrews have a mutation in their ion channel receptor, TRPV1, which makes it less sensitive to the "hot" chemical in chili peppers. As a result, the adorable critters happily gobbled up corn pellets laced with capsaicin (the compounds that give peppers their spice) while other mammals in the study avoided them.