Answer: White-Tailed Deer

If there’s one bit of greenery that none of us is clamoring to put on our salads, it’s most certainly poison ivy. Poison ivy, formally Toxicodendron radicans, is a poisonous plant found throughout Asia and North America, and best known for the horrible itchy rash its sap causes.

Despite our very strong aversion to getting anywhere near the stuff, we’re the only animal that has an aversion to it. For years it was believed that the irritant in poison ivy, the urushiol found in its clear sap, was a deterrent intended to stop animals from consuming it. The only animal the urushiol wards off, however, is humans–we’re the only creature that comes in contact with poison ivy that has a nearly universal allergic reaction to urushiol.

In fact, not only does urushiol do absolutely nothing to stop woodland creatures from eating poison ivy, but white-tailed deer have an outright preference for it. Given the option, the deer would gorge on mountains of poison ivy leaves and leave the rest of the forest greenery alone.