How to Find Ground Wasp Nests
If wasps are not causing a problem, leave the nest alone. Wasps are beneficial predatory insects that kill harmful pests.
Do not approach the nest during the day. Wasps go back into the nest at night, so return after nightfall to treat the nest.
Social wasps build their nests in higher spots such as in trees, or underground. Underground wasp nests are actually very similar to the familiar paper balls that aerial wasps build, it's just that the nest is located underground. The hardest part of eliminating this type of nest is finding the entrance. Wasp nests are seasonal. Unlike bees, only the mated queens survive the winter.
Look across an open area where wasps have been seen. You can spot them easiest under bright sunlight. They tend to fly in straight lines, so if you see several wasps flying in the same direction, they are probably going to or from the nest.
Set out bait to lure the wasps. When wasps find food, they carry it back to their nest immediately. Scoop a small amount of canned cat food or fruit jelly onto a paper plate and put it out where wasps have been spotted. Raw chicken skin, lunch meat and raw hamburger also work well.
Follow the wasps back to the nest, but don't get too close. The entrance is usually a hole in the ground that started off as a rodent burrow or other hole, but they can also build nests in walls, and in trees and bushes. Watch for adult wasps entering and leaving the hole.