Justin Schmidt, an entomologist at the University of Arizona, has been stung by insects hundreds of times over the course of his career. In the mid-1980s, he decided to categorize these experiences scientifically. The result is a "pain index" that reads almost like a wine tasting guide. At the low end of the scale, you'll find species like pharaoh ants and the Costa Rican wasp Polybia diguetana. At the scale's upper limit are the tarantula hawk wasp (top photo) and bullet ants. Read the full article.