A clear sign you have found an in-ground wasp nest is if you see wasps congregating near the ground. To find the entrance of the nest, look for a mound of dirt or sand with a central hole large enough for your pinky to fit through. Another obvious indicator is a hole surrounded by piled-up soil with trails in it. Some species of wasps will drag dead bugs back into their nest to feed offspring, creating little streaks in the soil leading up to the hole. You can monitor any suspicious holes in your yard to see if wasps make their way in or out of them.
What Kind of Wasps Make Nests in the Ground?
At least 1,400 different wasp species nest underground. However, many of these species are so rare you’re unlikely to come across them. The most common types of ground-dwelling wasps you may encounter are:
- Digger wasps
- Weevil wasps
- Sand wasps
- Cicada killer wasps
These wasp species will lay eggs underground. Then, the wasps of the colony will catch bugs and carry them back to the nest for their young to eat. Depending on the species, wasps either dig their own tunnels or take over tunnels dug by other creatures.
Are Ground Wasps Aggressive?
Most subterranean wasps are solitary and non-aggressive. The most common ground-nesting species that is considered aggressive is the yellowjacket. They are aggressive because they have a colony to protect. If disturbed, they may sting humans and pets.
- The majority of ground-dwelling wasps are not aggressive.
- Yellowjackets are aggressive, and will sometimes live in the ground.
- Many underground wasp species are solitary, so you are not likely to encounter a large swarm.
Solitary underground wasps are not a danger to humans and animals. There are usually very few of them in one area and they do not show aggressive behavior. So, most ground wasps are harmless.
3 Ways to Know if You Have an Underground Wasp Nest
The idea of wasps tunneling around your property can be anxiety-inducing. There are a few things to look for if you are concerned about wasps nesting in your yard, including wasp behavior and entrances to their underground nests.
Wasps Congregating Close to the Ground
If you find a lot of wasps hanging out near the ground and crawling around it, there is a good chance they have a nest nearby. Wasps hover and gather near their nest. So, look for wasps taking off from the ground, as well as wasps swooping down to land on the ground. This may signify the entrance to a nest.
- If there are a lot of wasps around with no signs of another nest, it is possible they are nesting underground
- It is more likely that the wasps are nesting underground if you see them hovering around the ground and gathering on it
- Watch for wasps bringing materials or food to the ground, such as dead insects, which could indicate their nest is underground.
While yellowjacket and other wasp nests can be underground, wasps can also nest in shrubs, tree stumps, and wood piles, so be sure to check for signs of nests elsewhere. Wasps may even be nesting underneath your deck.
Dirt Mounds with Entrances
To find a wasp nest in the ground, look for a small mound of dirt with an open hole in the center. The entrance to a wasp nest will be ½ to 1 inch (12–25 mm) in diameter. If you see wasps crawling around a hole that fits this description, you’ve found a wasp nest.
- Conical mounds that have a dime-sized hole in the center are entrances to underground nests.
- Wasp nests may look similar to ant mounds, except wasp nests have a much larger entrance hole.
- Depending on the soil, the mounds may have tiny stones piled around them as well.
- Some wasp species create underground colonies with multiple entrances.
A single wasp colony may have several mounds with entrance holes. Multiple entrance points allow the wasps to enter and leave the colony even if one tunnel collapses. You are more likely to find multiple entrances if the underground wasps are a social species, such as yellow jackets.
Trails Around the Entrance
Look closely at the dirt you see mounded around the entrance to the underground tunnel to determine if it’s the entrance to a wasp nest. Wasp nests will have thin streaks and lines in the loose soil around the entrance. This is due to the fact that wasps carry insects back to their nest to feed the colony. As the wasp drags the insect through the dirt to bring it inside the nest, it leaves small lines and tracks.
- Look closely around the entrance of the nest for small lines and tracks in the dirt—these marks mean wasps have brought food back to the nest.
- Species like the cicada killer build up soil around the hole and leave a distinct trail leading into it when they drag prey into their nest
- If you are unsure if a hole is actually a nest, you can watch it for a while to see if wasps enter or exit
The entrances made by wasps can be hard to see if they are tucked away under leaf litter or shrubbery. Be sure to check for holes where the soil is driest because that is the easiest soil for wasps to dig tunnels in. This is also where you’ll see the best evidence of the tracks left by foraging wasps.
How Do You Get Rid of a Wasp Nest in the Ground?
Because yellowjackets and some other wasp species can act aggressively, it is not a good idea to try to get rid of an underground wasp nest yourself. It is safest, fastest, and easiest to call a pest control service that specializes in stinging insects. Attempting to harm an active nest can result in a swarm of wasps trying to sting you. Using gasoline is ill-advised as well, since you will ruin your soil, pollute groundwater, and damage the ecosystem of your backyard. If you really want to destroy an underground wasp nest yourself, use this method:
- Once you’ve identified the holes wasps use to enter their nest, mark them with a flag.
- Wait until nightfall.
- Once it is dark, use glassware such as a mason jar or bowl to completely cover each hole.
- Press the rim of the bowl or jar into the ground so wasps cannot escape from beneath the container.
- Pile dirt around the edges of the container and weigh it down by placing small, heavy objects on top of it to hold it in place
- Wait for 2–4 weeks, checking on your containers periodically to make sure wasps are not escaping
The goal of this method is to trap the wasps underground so that the colony starves and dies out. This can take several weeks, but it will help you eradicate wasps living below ground on your property.
How Do You Find an Underground Wasp Nest?
If you have wasps on your property and cannot find a nest, there are signs you can look for to determine if these wasps are nesting in the ground.
- Look out for wasps spending a lot of time hovering around or walking on the ground in specific areas.
- If you see wasps carrying dead insects to the ground, they may be bringing that food to an underground nest.
- A mound of dirt or sand with a hole you could fit your finger into is likely an entrance to a wasp nest.
- Multiple holes going straight into the ground may indicate wasp nesting activity.
- Some wasps leave trails leading into the holes they create.
Tunneling wasps are an important part of the ecosystem, so it is best to leave the wasps alone. However, yellow jackets will be aggressive around underground nests. If you find yellowjackets nesting in the ground, contact a professional pest service so you don’t have to do the dangerous work of dealing with stinging insects.