WILLIAMSVILLE, N.Y. -- If you think yellow jackets are especially aggressive lately, you're not alone. The wasps, commonly mistaken for bees, are enjoying a longer than normal lifespan thanks to the mild temperatures we've been having.

At one Williamsville home, an army of yellow jackets, aggressive and annoying and as many as 3,000 strong, enter a small hole in the house's siding, where inside they're preparing for winter.

"Right now, they're aggressive because it's getting towards the end of the season and their populations are at their peak," said Marc Potzler, Buffalo Exterminating.

If yellow jackets seem hyper hostile this time of year, it's because they're preparing to die. Their final duty is to feed the queen, who will be the winter's sole survivor and lay her eggs in the spring. 

"Yellow jacket nests usually start in the spring. The queen that spent the winter hibernating basically starts up a nest and it's just her in the spring with a nest that's the size of a golf ball," Potzler said.

At Buffalo Exterminating in Orchard Park, where they once pulled a beach ball-sized yellow jacket nest from a barn, business is booming, as the wasps have had more time to feed and pester humans.

"Why are they so aggressive this time of year? 'Cause the workers are working as hard as they can to get as much nutrition as they can for those new queens," said Potzler.

"People are calling in left and right. We're struggling to get all the work done."