Expert: Jack DeAngelis - 7/22/2009

Question
Hi I noticed a paper wasp nest hanging from under the roof of my house.  Its about the size of a football, i see black wasps (i think) flying in and out of it.  I was thinking of waiting until oct/nov for the wasp to be dormant but the thing is the nest is very close to the attic window (the attic is not in use), would that be dangerous ?? is there any way i can take of it without spending hundreds on the exterminator?? help

Answer
Sam,

There are two kinds of wasp nests. Paper wasps make nests that are "open", you can see individual cells because they don't have the paper covering. In the other nest type the cells are completely enclosed in a paper envelope. The enclosed nest is made by the vespid wasps or yellowjackets. The distinction is important because vespid wasps tend to be much more aggressive than paper wasps and large vespid nests are therefore more dangerous.

Here's a picture of a large paper wasp (open type) nest http://www.livingwithbugs.com/epw.html made by the European paper wasp. And here's a picture of a typical yellowjacket nest (enclosed) http://www.livingwithbugs.com/yel_nest.html for comparison. To complicate the picture even further yellowjacket wasps build these nests both above ground and below ground.

You describe your nest as enclosed like a "football" so it is probably a vespid wasp nest perhaps the baldface hornet, a type of vespid wasp which is mostly black.

If the attic window is screened or never opened it is probably safe to leave the nest alone until after the first hard frost. However, if there's a possibility that the wasps can gain entry into the attic and then into the house I'd probably destroy the nest.

You can treat the nest with a "wasp & hornet" type spray (see the second page cited above). The trick in your case will be to get close enough to spray it. It might not be safe to be standing on a ladder because the wasps can swarm when the nest is first sprayed.

The best option is to leave it alone until winter. If the nest is threatening now try to figure out a way to get close enough (10') but still have an "escape route" in case the wasps swarm.

Post a follow up if you have questions.

Jack DeAngelis, PhD
Extension Entomologist (ret.)
My website about home and garden pests: http://www.livingwithbugs.com