Pain is a subjective experience, but I think we can all agree that given the choice between being stung on one's arm or one's delicate bits, you're going to go with the arm every time. But are your nether-regions really the most painful spot an insect could assault? One brave scientist decided to answer this question... using himself as a test subject.
Recently, Cornell University graduate student Michael Smith went to the trouble of stinging himself with bees over the course of 38 days. 25 locations were included in the study, each receiving three stings each. He then scored the level of pain caused on a scale of one to ten, using stings on his forearm as the average.
Turns out that, yes, having a bee go to town on your most precious of parts is quite, quite painful. In fact, in Smith's testing it came in at #3 with a score of 7.3, with his upper lip in second place at 8.7.
As for the winner? His nostril, clocking in at a 9.0 on the scale. The paper describes the rather unpleasant experience:
Stings to the nostril were especially violent, immediately inducing sneezing, tears and a copious flow of mucus. The sting did autotomize in the nostril (self-severed when the bee was pulled away). The copious mucus flow, however, may help prevent subsequent stings to the area during a natural attack.
As for the least painful place? That would be your skull, so if your would-bee torturer offers you the choice, go for that.