“The implications [of this question] are… profound,” says entomologist Michael Raupp. “Reckless flying, passing out in frosty beer mugs, hitting on crane flies instead of mosquito babes. Frightening!” Still, no major studies have been conducted to determine if mosquitoes get hammered—or even woozy—after ingesting human blood with a higher-than-normal alcohol concentration.
We do, however, know there’s at least one common bloodsucker that definitely can’t hold its Guinness. In 1994, Norwegian scientists Anders Baerheim and Hogne Sandvik wondered how potent beer might affect “the appetite of leeches.” “Six leeches,” the pair reported after their ensuing experiment, [PDF] “were dipped briefly in two different types of beer (Guinness or Hansa Bock) or in water (control) before being placed on the forearm of one of us… After exposure to beer, some of the leeches changed behavior, swaying their forebodies, losing grip, or falling on their backs.”