Identifying what you have before you decide anything
Almost every wasp decision gets easier once you know which of three insects you are looking at, and you can do it from a safe distance. The nest is the fastest clue. An open comb hanging from a short stalk, with cells you can count from below, is a paper wasp. A gray enclosed envelope with a single opening is a bald-faced hornet. No visible nest at all, just wasps going in and out of a hole or a gap, is a yellowjacket. Size backs it up. The University of Minnesota measures yellowjackets at three eighths to five eighths of an inch, bald-faced hornets at about seven eighths, and paper wasps at half an inch to an inch. Paper wasps also fly with their long legs trailing, which is noticeable once you know to look. Flight behavior finishes it. Paper wasps drift and land often. Yellowjackets move fast and direct, usually toward the same point on the ground or a wall over and over. That identification, made from twenty feet away, decides whether the rest of this is a five-minute job or a phone call.
A short season with a sharp peak
The wasp year in Minneapolis is compressed, and knowing its shape tells you when action is cheap and when it is risky. Late April and May: overwintered queens leave bark, woodpiles, and sheds and begin nests alone. A comb is a few cells. This is when a broom does the work of a service call. June and July: the first workers take over foraging while the queen stays inside laying. Colonies expand without drawing attention, and the ground nests that cause trouble in September are being built now. August and September: the peak, with nests at their largest, defense radius at its widest, and foraging shifting toward sugar. This is when decks become contested and hidden nests get found the hard way. October: colonies produce next year's queens and males, then break down as temperatures fall. First hard freezes: over. Workers and the founding queen die, mated queens disperse into shelter, and the nest becomes an empty artifact that will never be used again.
The nest under the lawn that nobody spotted
The bad sting stories in Minneapolis almost always involve a nest nobody knew about, not the one on the porch. A yellowjacket colony underground shows nothing but a small opening, and that opening is usually against something: the base of a shrub, the edge of a bed, a slope, the gap under a step, or an old burrow left by another animal. Everything else is below ground. What triggers the whole colony is shock carried through soil. Mowing, edging, raking, a shovel going in for a plant, and repeated footfalls on soft ground all qualify. Yellowjackets answer as a group rather than one at a time, they follow, and they mark a target chemically so more of them come. The national numbers show who this happens to. The CDC counted 788 United States deaths from hornet, wasp, and bee stings between 2011 and 2021, and 84 percent were male, matching the people running mowers, trimmers, and outdoor equipment. Stopping to watch an unfamiliar patch of yard for a minute before you start is the entire preventive step.
What to do in the first minutes after a bad sting
Most stings need ice and nothing more. A small share are medical emergencies, and the difference is visible within minutes. A normal reaction stays local: pain, redness, heat, and swelling around the sting, sometimes spreading a few inches. Cold, an antihistamine, and time handle it. A systemic reaction shows up somewhere else entirely. Hives spreading across the body, swelling of the lips, tongue, or throat, wheezing or difficulty breathing, dizziness, a fast pulse, nausea, or vomiting. That is an immediate call for emergency help and a prescribed epinephrine injector if one is available, used without waiting to see whether it improves. Multiple stings are their own category. If a ground colony has stung someone many times, get them away from the site first and then seek medical advice regardless of allergy history, because venom load matters on its own. Anyone who has had a systemic reaction before should not go near a nest again. Allergy specialists put the chance of a similar or worse reaction on a later sting at 60 percent.
wasps in the walls of an older house
The second common problem is a colony that has moved into the building, and it is the one that goes wrong most often when people handle it themselves. The usual entries are the seam where soffit meets siding, loose or gapped trim, a torn gable or soffit vent screen, and openings around pipe and cable penetrations. a wasp needs very little space, and once inside, the colony builds into a framed cavity that is dark, dry, and undisturbed all season. What you see outside is a few wasps at one point. The nest can be well away from that entrance inside the wall, which is why treating the wrong gap does nothing. The rule that matters more than any product: do not seal the opening while the colony is alive. wasps cut off from their exit chew toward light and air, and in a wall that direction is often into a room. Treat, wait several days, confirm nothing is moving, then close it. And close it properly, because the opening is why the nest was there at all.
Two quotes, one nest, very different numbers
Price differences on wasp work usually come down to what is included rather than one company charging more for the same thing. Ask each of them, in the same words, whether the price covers killing the colony only, removing the nest as well, or also closing the opening the wasps used. Those are three jobs. A lower quote that stops at the first is smaller, not dishonest, and the gap turns up next spring at the same soffit. Ask what happens if there is still activity a week later. A colony deep in a wall sometimes needs a second application, and the answer to that is worth having before you decide. Ask when they will treat. Willingness to schedule a hidden nest at dusk indicates someone doing the job properly, since foragers away from the nest at midday survive a daytime treatment. Ask what they actually found. A technician who can say where the nest sits and how they traced it has done real work rather than emptying a can at a hole.