While foraging for food, insects detect floral scent molecules in the air. Wind currents can carry these molecules up to thousands of feet from their original source to where bees have their hives.
“Many insects have nests that are up to 3,000 feet away from their food source, which means that scents need to travel long distances before insects can detect them,” said Jose D. Fuentes, professor of meteorology and atmospheric science, Penn State. “Each insect has a detection threshold for certain kinds of scents and they find food by moving from areas of low concentrations of scents to areas of high concentrations.”
Read more here: Bees’ ability to forage decreases as air pollution increases