This is a banner year for yellow jackets and I want to make everyone aware that they should not be spraying these wasps when they see them entering an opening in a building. The nest is already in the building and is quite large at this time of year. Spraying over the counter wasp spray will drive them all into the building which is very dangerous.
Now some information about yellow jackets you may find interesting…

When a yellow jacket stings you, it pierces your skin with its stinger and injects poisonous venom that causes sudden pain. You may also experience inflammation or redness around the sting a few hours after being stung. Fatigue, itching, and warmth around the injection site are also common symptoms for many people. Yellow jackets are more aggressive than other stinging insects such as wasps, hornets, mud daubers or bees.
Yellow jackets can both sting and bite — they will often bite to get a better grip to jab their stinger in. Since they don’t lose their stinger, they can sting numerous times, and will do so unprovoked. Yellow jackets are at their peskiest in the late summer or early fall. There are no more developing larvae to feed so workers are foraging randomly for themselves. They can become increasingly aggressive in gathering food and are more likely to sting during this time.
Wasps and yellow jackets are beneficial insects. They feed their young on insects that would otherwise damage crops and ornamental plants in your garden. They can also feed on house fly and blow fly larva.