There are about twelve different species of yellow jackets in the Portland Metro area. Some are called hornets. They are a type of aerial nesting yellow jacket. Its nest visibly hangs in the air on a bush, tree, under the eave of your house, or some place similar. Their colors may vary. The bald-faced hornet is black & white, as opposed to black & yellow.

Both yellow jacket & hornet nests are the same in structure, whether in the air, in the ground, or in the wall of your house. It’s a paper nest made of wood fibers. Unlike the paper wasp nest, a yellow jacket nest has a paper coating that is gray or brown in color. It resembles a paper machete ball with an entrance hole towards the bottom.

When yellow jacket queens first start their nest in the spring the nests are quite small, like a golf ball. Towards fall their nests can be very large. We’ve been in attics where the outer paper coating of the nest was five feet in diameter. However, most nests get to be just a bit bigger than a basketball with a few thousand yellow jackets in them. At the end of their cycle the queen will raise other queens for next year. Those queens leave the nest to find a place to individually hibernate for the winter, while the original nest dies out, never to be used again.

Yellow jackets are very aggressive & should be left to a professional to deal with. If you find them going in & out of a hole in your house you should have it exterminated immediately. They have a mandible like a carpenter ant & can chew through your wall quite easily. In most cases they’ll take a couple of weeks to do so, but if you spray their outside hole with a can of spray or caulk it, & they get desperate for another way out, they can come through much sooner.