Wire Web Specials Warmth fosters a yellow jacket boom Thirst and hunger are driving the insects far from their nests. They have stung toddlers in playgrounds, golfers on golf courses and babies in their mothers' arms. It's estimated that encounters between yellow jackets and people, and perhaps the overall numbers of the wasps, are 20 to 30 times greater than normal.
Experts attribute the large population to a yearlong sequence of weather conditions.
Last winter had few nights with temperatures in the 30s or 40s. Normally, such a chill kills off entire nests of yellow jackets except for young queens, which go into hibernation. With the unseasonable warmth of a year ago, some nests survived and grew. The queens reproduced instead of hibernating. Then last spring, thanks to the winter's rains and moderate temperatures, yellow jackets discovered a bumper crop of their favorite foods, caterpillars and flies.