Raucous parties lead to abandoned alcohol, and the next morning, hosts may wake up to buzzing after-party guests — flies. In a study conducted at the University of California, entomologists found that flies from the Drosophilia species actually prefer beer to sucrose, despite its minimal sugar content and bitter taste. The cause of their attraction was determined to be Gr64e, a receptor for glycerol. Flies with defective versions of this receptor showed a weakened preference for beer. These flies primarily seek out sugars as a food source since it is easily metabolized, and they are usually not attracted to alcohol due to its low sugar content. In addition, the team found that the flies didn’t seem to rely on olfaction to find the alcohol — even flies with removed olfactory receptors shared the preference for beer. Like many partygoers, the flies seem to taste first and ask questions later.

Source: Science Daily