Enjoying a cold brew on a warm night? You might be giving mosquitoes a subtle invitation. A recent study at a music festival in the Netherlands found that people who had had at least one beer were about 35% more attractive to mosquitoes than those who hadn’t. 

The setup: researchers recruited 465 volunteers, had them answer questions about their habits (diet, hygiene, etc.), then measured how many mosquitoes would land on their arms when given a choice between human skin vs a sugar feeder. 

What’s making beer-drinkers more delicious to bugs isn’t fully nailed down yet. It doesn’t seem tied directly to how “drunk” someone is, but rather changes in body odor, the volatile compounds your body emits after beer consumption. 

Other surprising findings: mosquitoes also favored folks who had smoked cannabis in the last day or two, or who slept with someone the night before. And if you’ve showered recently or used sunscreen, you may be less of a target.