Yellow Jackets in the Walls: How We Find Nests You Can't See

This week in pest control around the New River Valley kept us busy. Our technicians were out on routine monthly commercial services and quarterly home services in Pulaski and Dublin, and took care of several Claytor Lake homes on the Dublin side of the lake. Meanwhile we handled a mouse problem in Radford, big wolf spiders and a ground nest of yellow jackets out near Prices Fork, and two separate jobs with yellow jackets living inside the walls of a house.

Those last two are worth talking about, because this is the time of year they happen most.

Why yellow jackets are worse in the fall

A yellow jacket colony starts in the spring with a single queen and grows all summer long. By late summer and early fall it can be at its largest, with hundreds or even thousands of workers. As their natural food sources dry up, they get more aggressive and more interested in people, trash cans and anything sweet. That's why so many stings happen in September and October.

Most nests are in the ground or tucked into shrubs, but some colonies move into a wall void, a soffit or the space around a chimney. From the outside all you see is a steady line of yellow jackets going in and out of one small gap.

Finding a nest you can't see

Over in Riner, yellow jackets had built a nest in a wall void above an attic closet door. In Christiansburg, another colony was getting into the house around a chimney and finding its way into a bedroom closet and the bedroom itself.

A living nest gives off heat, and a thermal imaging camera picks that up right through the drywall. That let us find exactly where each nest sat inside the wall, without guessing.

The thermal camera shows the nest as a bright warm spot behind the drywall.

In Christiansburg we cut away just the section of sheetrock over the nest and removed the nest and the live yellow jackets, instead of opening up half the wall to look for it.

The nest behind the sheetrock, after we cut it open.

What not to do

If you see yellow jackets going in and out of a gap in your siding or around a chimney, it's tempting to caulk the hole shut or spray it with a can from the hardware store. Please don't. Sealing the entrance traps an active colony inside the wall, and they'll look for another way out. Sometimes that new way out is through the drywall and into your house, which is exactly how they end up in closets and bedrooms.

Spraying the opening usually doesn't reach the nest either, and it stirs up the colony while you're standing right in front of it.

The colony will die off once we get a few hard freezes, and only the new queens survive the winter somewhere sheltered. But if they're coming inside now, or the nest is somewhere your family walks every day, it's worth taking care of before someone gets stung.

If you're seeing yellow jackets around your home in Blacksburg, Christiansburg, Radford, Dublin or anywhere else in the NRV, give New River Pest Control LLC a call and we'll find the nest and get you taken care of.