For non-aggressive wasps I've had great luck spraying nests with this Spectracide wasp remover in the evening. For a nest up high in an eave, soffit, or tree, this Gotcha pole adapter clamps onto the can so you can spray from the end of an extension pole and treat the nest from 10+ feet away instead of standing right under it. And for anything aggressive I wear this ridiculous-looking upper torso beekeeping suit and keep my distance. It seems silly, but trust me, I learned the hard way.
Most people asking what is a wasp are standing in a yard looking at something with a narrow waist and a bad attitude. The quick answer: a wasp is a stinging insect closely related to bees and ants, with a pinched waist, a smooth body, four wings, and — in the species that bother homeowners — a colony to defend.
The longer answer is more interesting, and more useful, because “wasp” turns out to be one of the loosest words in insect biology. It covers more than 100,000 described species, most of which are smaller than a grain of rice and completely harmless. Roughly a dozen matter to a homeowner in North America. Knowing which category you’re looking at is the difference between an afternoon of panic and simply walking away.
This guide covers what a wasp actually is, what all wasps have in common, what gets called a wasp but isn’t, and how much of it you need to care about. For how wasps live day to day and season to season, see the wasp behavior and biology guide. For telling species apart by sight, see the wasp identification guide.
Wasps belong to the insect order Hymenoptera — the group that also contains bees, ants, and sawflies. Within Hymenoptera, wasps sit in the suborder Apocrita, the “wasp-waisted” branch, named for the dramatic constriction between the middle and rear sections of the body.
Here’s the awkward part. There is no single feature that defines a wasp and excludes everything else. Bees and ants are both specialized offshoots within the wasp lineage — bees are essentially wasps that gave up hunting for pollen, and ants are wasps that traded flight for permanent underground colonies. So the working definition entomologists use is one of exclusion:
A wasp is any member of Apocrita that is not a bee and not an ant.
That’s not a cop-out; it reflects real evolutionary history. It also explains a lot of the confusion homeowners run into. It’s why hornets and yellowjackets are wasps even though people talk about them as separate things. And it’s why some wasps look nothing like the yellow-and-black insect you’re picturing.
Despite the sprawl, a few features run through the group.
The waist. The famous “wasp waist” is a narrow stalk called the petiole, connecting the thorax to the abdomen. It isn’t decorative — it gives the abdomen enormous flexibility, letting a female curl it forward and under to place a sting or an egg with precision. Sawflies and horntails, often called “wood wasps,” lack this waist entirely, which is why they’re grouped separately from true wasps.
Four wings, working as two. Wasps have two pairs of clear membranous wings. The smaller hind wing hooks onto the forewing with a row of tiny hooks called hamuli, so the pair beats as a single surface. In flight it looks like one wing per side. Vespid wasps — paper wasps, yellowjackets, hornets — also fold their wings lengthwise along the body at rest, a useful giveaway. More on the mechanics in the wasp wings guide.
A smooth, hard body. Wasps are largely hairless and often glossy. Bees are fuzzy, with branched hairs built to trap pollen. This single difference is the most reliable field distinction between the two, and it holds up better than color.
Chewing mouthparts. Wasps have functional mandibles. Paper wasps use them to scrape wood fiber and chew it into pulp for nest paper; predatory species use them to dismember prey. This is why wasps can gnaw at fascia boards, fence rails, and cardboard.
A stinger that used to be an egg-laying tube. In the stinging wasps, the sting is a modified ovipositor. That has one consequence worth remembering: only female wasps can sting. Males have no stinger at all — which is why male cicada killers can body-slam you all afternoon without doing a thing. And because a wasp’s stinger is smooth rather than barbed like a honeybee’s, a wasp can withdraw it and sting repeatedly. The full mechanics are in the wasp stinger guide.
Two completely different diets across one lifetime. Adult wasps run on sugar — nectar, honeydew, tree sap, fallen fruit, your soda. The larvae back at the nest eat protein, which in predatory species means insects the adults hunt and carry home. This split explains almost all late-summer wasp behavior around people, and it’s covered in depth in what do wasps eat.
More than 100,000 wasp species have been described worldwide, and entomologists broadly agree the real number is far higher; wasps are one of the most under-catalogued groups of animals on Earth. The overwhelming majority are parasitoid wasps — tiny, often under 5 mm, that lay eggs in or on other insects. You have thousands of them in your yard right now. You have never noticed one, and none of them can meaningfully sting you.
Size range is extreme. The smallest known insect of any kind is a fairy wasp, a fraction of a millimetre long. At the other end, the largest species have bodies pushing two inches with wingspans over four — see the biggest wasp in the world.
Now the number that actually matters: only around 1,000 wasp species are social, living in colonies with a queen and workers. That’s well under one percent of the group. And of those, a US homeowner realistically encounters about a dozen:
Everything else you see is, statistically, a solitary or parasitoid wasp minding its own business. The breakdown by group is in types of wasps, and which species live in your part of the country is in the wasps by state guide.
Social wasps build a shared nest, raise young cooperatively, and defend the colony as a unit. This is the only group with a meaningful sting risk for homeowners, because the sting is defensive and collective — disturb the nest and you’re dealing with a crowd. In temperate North America these colonies are annual: a single queen starts a nest in spring, the colony peaks in late summer, and it dies at frost, with only mated future queens surviving to the next year. The full arc is in the wasp life cycle guide.
Solitary wasps have no colony, no workers, and nothing to defend but themselves. A single female builds a nest, provisions it with paralysed prey, lays eggs, and leaves. Mud daubers, cicada killers, digger wasps, potter wasps, and spider wasps all work this way. They can sting but essentially never do unless handled — there is no colony to protect, so aggression has no payoff for them.
Parasitoid wasps lay eggs in or on a host insect, and the larva consumes it from inside. This sounds grim and is ecologically enormous: parasitoid wasps are one of the main forces holding down caterpillar, aphid, and beetle populations, and several species are reared commercially for pest control in greenhouses and farms. See parasitic wasps for how this works.
The name gets attached to plenty of unrelated animals:
And the reverse, insects that are wasps but don’t read as one:
Two other common mix-ups worth settling. Wasps don’t make honey — with one curious exception, the Mexican honey wasp of south Texas, which does store small amounts. Details in do wasps make honey. And wasps do pollinate, just inefficiently compared with bees, because they lack pollen-carrying hairs; fig wasps are the famous exception, where plant and insect can’t reproduce without each other.
For most people, a wasp sting is painful, swells for a day or two, and resolves on its own. The real risks are narrower and worth naming plainly:
Aggression varies enormously by species and season. A solitary wasp near your flowerbed in June is a non-event; a ground nest of yellowjackets in September is not. The reasons are in are wasps aggressive, and treatment is covered in the wasp sting treatment guide.
Yes, substantially. Social wasps are significant predators of caterpillars, flies, and other soft-bodied insects, hauling enormous quantities of pest larvae back to feed their young through the summer. Parasitoid wasps suppress crop and garden pests on a scale that would be expensive to replicate chemically. Wasps also do a modest amount of pollination, and wild figs depend on their own dedicated wasps completely — no wasp, no fruit.
This is a real argument for leaving nests alone when they’re genuinely out of the way — high on a barn, deep in a tree line, well away from doors and paths. In most of the country that colony will die at first frost and won’t reuse the nest. More on this in what do wasps do for the environment.
Identify before you act. A mud tube under the porch and a football-sized grey nest by the front door are entirely different problems, and treating the harmless one wastes effort while creating risk.
Handle it yourself only if all of the following are true: the nest is small, exposed, at a height you can reach standing on the ground, and belongs to paper wasps or mud daubers. Treat after dark when foragers are home and activity is lowest, wear covered clothing, use a jet-stream spray from the labelled distance, and have an unobstructed path to walk away.
Call a professional for ground nests, wall-void or attic nests, anything requiring a ladder, large late-season colonies, hornet nests, or any situation where a household member has a known sting allergy. Ladder work near a defended nest is where homeowners get seriously hurt — the stings aren’t usually the injury, the fall is. Methods and limits are in how to get rid of wasps and the complete guide to wasp nests.
Worth a note, because the search term is ambiguous: WASP in all capitals is also an acronym for White Anglo-Saxon Protestant, an American sociological term with nothing to do with insects. The insect word is much older, from Old English wæsp. Wasps have also picked up a fair amount of symbolic baggage over the centuries — covered in wasp meaning and symbolism.
A wasp is a member of the bee-ant-wasp order with a pinched waist, four wings, chewing jaws, and — in females — a stinger derived from an egg-laying tube. The category is defined mostly by what it excludes, which is why it covers everything from a nearly invisible parasitoid to a two-inch hornet.
Practically speaking: over 100,000 species, about 1,000 social, roughly a dozen relevant to your house, and only the social ones will defend a nest against you. Work out which of those you’re looking at, and the right response usually becomes obvious.