So, you’ve come across a strange, paper or clay structure hanging from your eaves or stuck to the side of your house. You want to know who left it there. Or, maybe you’re just interested in identifying wasp nests. Either way, we’re here to guide you through the world of wasp nests: the different types, how they are built, where to find them, and how many wasps to expect per nest. If you want to how to to get rid of them, check out our article, “How to Remove a Wasp Nest.”
Types of Wasp Nests
The most common types of wasp nests are made by yellowjackets, hornets, paper wasps, or mud daubers. Yellowjackets, hornets, and paper wasps all make a rudimentary type of paper out of chewed-up wood mixed with saliva which they then use to build a nest with multiple cells that are sometimes layered.
Yellowjackets often build enormous colonial nests underground with many tiers of cells. These are usually in abandoned rodent burrows, rotten logs, pipes, or other hollow structures. Some yellowjackets build hanging nests out in the open. Yellowjacket nests have a thick protective envelope on the outside of the nest and a single entrance. The first cell layer hangs from the inside of the envelope and each subsequent layer of cells hangs from the one above. Yellowjacket nests can have nearly 100 tiers of cells. The baldfaced hornet, which is actually a type of yellow jacket, typically builds its hanging pear-shaped nest in a tree. These can be up to two feet long.
The European hornet is the only true hornet that you’ll probably ever come across. They build a similar type of communal nest with an envelope that protects the tiered cells within. Hornet nests are typically built at least 6 ft. (1.8 m) above the ground in cavities of tree cavities or other empty spaces.
Unlike yellow jackets and hornets, paper wasp nests don’t have a protective envelope. They build open-air cells that hang from a stalk. It looks like an open umbrella from the side but from underneath, you can see the honeycomb-like cell structure. Paper wasps build their nests in protected areas such as under roof overhangs, tree branches, or even inside attics, sheds, and garages. Their nests are typically around 4 in. (10 cm) across.
Mud daubers are different. They are solitary wasps, so instead of big colonial nests, they build single-family dwellings. They also use a different material. Instead of wood, they mix their saliva with soil to make mud. They then build their nest on the side of a building or in a hole in the ground. A mud dauber nest can be tubular, round, or rectangular and typically measures 2-3 in. (5-6 cm) across. One species of mud dauber prefers to steal the nests of other mud daubers instead of making its own.
How Wasp Nests Are Made
Yellowjackets, hornets, and paper wasps all hang their nests from stalks. The wasps mold their paper material into the shape they want to create the stalks and the nests. The stalk is a narrow cylinder. They then build a thin layer radiating out from the stalk and construct cell walls on this layer. To make the envelope for yellowjacket and hornet nests, the wasps use multiple layers of paper to make it strong and protective. Yellowjackets can enlarge their underground spaces by wetting the dirt and digging.
Mud daubers moisten the soil and roll it into a mud ball using their mandibles and forelegs. They then transport it to their nesting site. When building on a wall, they spread the mud in a layer, beginning by building a single cell. They lay one egg in that cell then begin bringing insects or spiders back to the cell. Once the cell is full of prey for the larvae to feast on, the queen builds a roof over the cell and starts work on the next cell. Eventually, this collection of cells forms a three-dimensional tube, circle, or rectangle.
To build underground, the mud dauber digs a hole first, then lines it with mud before building a funnel over the entrance. A tube attaches this funnel to the entrance. Instead of being upright, it hangs upside down like a bell and is smooth inside. This prevents smaller, parasitic wasps from entering. Ground-dwelling mud daubers build cells within their holes and lay one egg per cell.
Wasp Colony Sizes
Social wasps have large families. Even though they start with a single female (the queen or foundress), they quickly grow as the larvae mature into workers. Yellowjacket colonies can have 1,500 to 15,000 individuals. Hornets live in populations of between 300 and 1,000 individuals. Paper wasps, with their much smaller nests, typically only number between 15 and 2003 individuals.
Solitary wasps have much smaller colonies. Not only do they lay fewer eggs, but mud daubers leave multiple paralyzed or dead insects or spiders in each cell for the larvae to feed on when they hatch. This is so that once the female seals her nest with a roof, she can leave and not return.
The black and yellow mud dauber builds a 25-cell nest, laying a single egg in each cell. The ground-dwelling mud dauber only lays between 2-5 eggs per nest.
How to Find Wasp Nests
As mentioned earlier, some species of wasps live underground. The best way to find an underground wasp nest (or any type of nest, for that matter) is to watch where the wasps seem to be coming and going from. If you can trace them back to their hole in the ground or other types of nest sites, at least you’ll know where the nest is – even if you can’t see it.
You may accidentally stumble across a nest, which is never a nice experience. Wasps can be very defensive of their nests. Social wasps secrete an alarm pheromone that calls the rest of the colony into action, meaning that you could easily find yourself in a swarm of stinging insects.
For that reason, try to find nests by monitoring wasps and checking cavities and sheltered areas before you, a family member, or a pet accidentally triggers their defense mechanism. Once located, it’s best to steer clear of the area. Wasps are useful to have around, so if they’re not in a place with a lot of foot traffic, you should leave them be. If you find a wasp nest in your house, however, you should get rid of it.
Where to Find Wasp Nests
It may be difficult to find hornet nests by monitoring insect activity. Hornets often hunt at night, so you may have some trouble following them home.
Nests may be found in cavities in rotten stumps, logs, the hollows of trees, poles, pipes, chimneys, children’s playground equipment, outbuildings, playhouses, attics, or in pet or poultry hutches. You can find them in pretty much any small, dark space. They may even build nests in the walls or the ceilings of houses.
Those that hang their nests also need shelter. These nests are usually on tree branches, in shrubs, under eaves, beneath outdoor furniture, in garages or barns, under porches or decks, under the roofs of porches, decks, and picnic shelters, on attic ceilings, or in just about any sheltered area from which they can hang a nest.
Mud dauber nests are usually in the same types of sheltered places as hanging nests. The only difference is that theirs will be pottery-type nests plastered to the wall instead of a hanging paper nest.
Wasps use paper or mud to construct all sorts of elaborate, multi-chambered nests. In terms of location, they are very versatile, building underground, in trees, and even in buildings. Wasps are perfectly happy to use someone else’s home as their own, living in man-made structures, rodent burrows, or stealing the nests of other wasps.
This article is a handy guide to find what kind of nest you may be dealing with, how many wasps could be living there, and where to find nests if you have seen wasps around.
We are going to leave you with an extra bit of advice. Wasps are important ecologically and are also helpful around the home and garden. If you can, it’s best to leave their nests alone and let them carry on with their business. Check out our article, “The Purpose of Wasps: Why Do We Need Them?” to learn more.