It's not just distraction. Cortisol bottoms out at night while histamine activity rises, and mosquitoes themselves are built to hunt hardest at dusk and dawn.

Roughly 1 in 5 people get bitten far more than everyone around them. Blood type, sweat chemistry, exercise and genetics all contribute, and the beer connection remains an unsolved mystery.

The CDC has confirmed 48 West Nile cases by June 30, far above the usual 10, with Arizona hardest hit as officials urge simple precautions over the July 4 weekend.