ROCHESTER, Wash. -- Yellow jacket stings peak every fall, according to entomologists.
But they've never seen a fall like this in Rochester, south of Olympia.
"This is the worst in 20 years that I can recall," said Rochester School District Superintendent Kim Fry.
Fry has had to hire private exterminators for the first time to help clear yellow jacket nests off school grounds.
The brightly-colored play structure at the primary school has been off-limits to students a couple of times every week since the school year started.
"I'm not sure of the species of the bee, other than they're aggressive," said mother Heather Couillard, whose daughter got stung four times over a nine-day period.
Couillard said her daughter now is allergic to bee stings and needs to have medication stored at the school. Her mother had to get a doctor's note to keep her from going outside for recess.
Walter "Steve" Sheppard, Chair of the Washington State University Entomology department said the bugs yellow jackets rely on for food are dying off as it gets cooler, making yellow jackets more aggressive as they search for food.
He did not think there are more yellow jackets around this year than in past. Most will die off after the first freeze, according to Sheppard.