When a wasp nest is active you will see wasps entering and exiting it on a regular basis. During the spring the wasps will be very busy collecting insects to feed the queens larva and later in the heat of the summer and into the fall they will start harassing humans for their sweet foods like ice cream and snacks. Knowing there are wasps on your property is usually a good sign there is a nest somewhere. If you find a nest on your property and no wasps can be seen flying around it or in and out of it you can assume the nest is dead. Removing this nest would be easy and you would not need to call a professional to help you get rid of it. Was nests do not last long in their natural habitat. They tend to survive for four or five months and then die off when it gets cold. As soon as temperatures start to drop during the day time, below 20 degrees wasps tend to die off and their nests become vacant. If you have a wasp nest on your property you can try spraying it on your own or hire a professional to take care of it. Its important to know that failing to kill a wasp nest will make the wasps very angry. They are able to identify human faces and will remember you. They will often seek out humans who attacked their nest and chase them around obstacles, dodging other humans and even waiting over water for you to come up for air, so when treating a wasp nest do it right, the first time. That or hire a professional, experienced and licensed exterminator to do it for you.
Wasps start building their nests in the mid to late spring when the weather is getting warm. When the weather gets cooler in the late fall the wasp works and original queen die off. Before this the queen will produce a group of females and males that are sexualized. These sexualized males and females will mate and the males will die off. The females, now pregnant leave the nest to find a place to hibernate for the winter usually under tree bark. The rest of the nest, including the sterile female workers, the sexualized males and the old queen all dies off. So if you find a wasp nest on your property in the late fall or winter then likely hood is the nest is dead. That is, if the nest is outside. Wasps, especially yellow jacket wasps are small enough that they can enter crevices and build nests in the walls of human homes. This often allows them to stay active through the winter and create multi-generational nests that can continue being active through out the winter and even for decades. Finding these nests is much more difficult than finding a wasp nest on the exterior, in a bush, on a tree or on your home. Treating a nest that is inside of your wall or attic is much more difficult and demands a professional for safety purposes. A wasp nest in a brick wall is not something you can treat on your own so call a professional to handle it.