The Schmidt sting pain index is a pain scale rating the relative pain caused by different hymenopteran stings. It is mainly the work of Justin O. Schmidt, a former entomologist at the Carl Hayden Bee Research Center in Arizona. Schmidt published a number of works on the subject, and claimed to have been stung by the majority of stinging Hymenoptera. His original paper in 1983 was a way to systematize and compare the hemolytic properties of insect venoms. A table contained in the paper included a column that rated sting pain, starting from 0 for stings that are completely ineffective against humans, progressing through 2, a familiar pain such as that caused by a common bee or wasp sting, and finishing at 4 for the most painful stings; in the original paper, only the bullet ant, Paraponera clavata, was given a rating of 4. Later revised versions of the index added Synoeca septentrionalis, along with tarantula hawks as the only species to share this ranking. Descriptions of the most painful examples were given, e.g.: "Paraponera clavata stings induced immediate, excruciating pain and numbness to pencil-point pressure, as well as trembling in the form of a totally uncontrollable urge to shake the affected part." Schmidt repeatedly refined his scale, including a paper published in 1990, which classifies the stings of 78 species and 41 genera of Hymenoptera, and culminating in a book published in 2016. An entry in The Straight Dope reported that "implausibly exact numbers" which do not appear in any of Schmidt’s published scientific papers were "wheedled out of him" by Outside magazine for an article it published in 1996. In September 2015, Schmidt was co-awarded the Ig Nobel Physiology and Entomology prize with Michael Smith for their Hymenoptera research. Overview Schmidt's pain scale of Hymenopteran stings is organized into levels, ranging between 1 and 4, with 4 being the most painful. However, insect stings that feel very different can be put into the same level. Thus, later versions of the scale always include a brief description of his experience being stung by each type of insect. Pain Level 1 Some of the insect stings Schmidt considered to be at a pain level of 1 include the Southern fire ant, the graceful twig ant, the Western paper wasp, the urban digger bee, and most small bees. The duration of the pain of insect stings categorized into Pain Level 1