Why yellowjackets are so active in the fall

Wasps particular nuisance in fall season before nests ‘shut down’

Yellow Jackets are particularly active in the fall, typically until the first hard frost of the year hits -- here's why.

Yellowjackets seem to have been out in full force this summer, but they aren’t finished yet: The social wasps will be particularly active in the fall.

While bees are strictly vegetarians, wasps like yellowjackets thrive on protein. They usually eat other insects, but if those are hard to find, they look for other things to eat.

And at this time of the year, their favorite places to dine tend to be where humans like to gather, too.

Entomologist Mark VanderWerp, manager of education and training at Rose Pest Solutions, says there is a biological reason why yellowjackets are so active right now.

“If you find a nest in late May, early June, it might be the size of a golf ball or the size of a tennis ball, and so it’s not really causing any problems,” VanderWerp said. “But as the season goes on, and the queen lays more and more eggs, and the workers fill up, all of the sudden you get this massive colony.”

In the fall, those nests begin to essentially shut down.

“When that happens, everything kind of goes haywire,” VanderWerp said. “All the workers that were building the nest, maintaining the nest, guarding the nest, they kind of don’t have a job anymore. That’s where they really start bothering people.”

Related: Ticks still a risk in the fall: What to know

Yellowjackets are drawn to strong food odors, and some are particularly attractive to them -- especially the sweet stuff. VanderWerp says the wasps are attracted to anything sugary, like sodas, juices, suckers and popsicles.

“Especially if it’s fruit based, sugar based or protein based -- like a chicken sandwich -- that is super attractive to these things this time of year,” VanderWerp said.

Which is why you’ll find so many wasps at cider mills in the fall, buzzing around cider, donuts and other sweet treats. Other spots also carry a bigger risk for yellowjackets, like outdoor trash cans and outdoor dining tables that aren’t being wiped down regularly.

Yellowjackets can sting several times. If one comes your way, it’s best not to swat at them. VanderWerp says to move slowly when approached by a wasp, as wild motions, like batting at them, will “increase your risk of being stung.”

The wasps are typically active until the first hard frost hits.

If a nest is out of the way, it’s best to leave it be. However, VanderWerp says it is a good idea to call a professional for help if you have a ground nest in a high traffic area, or a nest inside of a wall -- that can actually damage the structure.

Related: Bee, wasp, hornet stings have been on the rise in Wayne County

About the Author:

Dr. McGeorge can be seen on Local 4 News helping Metro Detroiters with health concerns when he isn't helping save lives in the emergency room at Henry Ford Hospital.