I don't entirely agree with that. I've pulled in a few swarms in after dark without any problems. Swarms in a tree, or bees in a weird table saw looking thing with them still bearding all over the outside of the box. I don't know about the drink part either...I have drank a few beers while watching my bees from only a few feet away. My money is on body odor. Working in the sun all day? Sweaty and stinky, now I have noticed that if I have been busting my rump and drenched in sweat, I have been nailed just walking past the hives, even though I didn't disturb them. Same thing with the guy that repaired my fence, he saw me walking past them with a pair of shorts on and a tee-shirt, no issues. When he was working on the fence and getting sweaty, he got nailed. Took a break after that. Started to sweat again, got nailed again! So for the next day, anytime he started to break a sweat, he took a break and NEVER had any more hits.Rule number one Never Beekeep at night!