The four wasps you are most likely to be dealing with
Start with what it is, because the answer changes what a reasonable response looks like. Native paper wasps hang an open comb from a short stem under eaves, rails, and light fixtures. You can count the cells from below. Small colony, modest defensive range, and the easiest thing on this list to handle yourself in spring. The European paper wasp looks similar but hides its comb in a cavity, which is why people meet it by reaching into a grill or a post. Same modest colony, much worse discovery. Bald-faced hornets build the gray enclosed football in a tree or a shrub. Penn State puts their range across nearly all the contiguous states. The colony is large, the nest is sealed, and outside spray mostly hits paper. Yellowjackets nest out of sight, underground or in a void, and defend the entrance as a group. They are behind most multiple-sting incidents, and they are the reason the advice on this page is cautious about anything hidden.
A Kansas City calendar for wasps
The same nest costs different amounts of trouble depending on the month you notice it. April and May: overwintered queens come out of woodpiles and sheds and start building alone. A comb is a coin-sized patch of cells. Check porch ceilings, window heads, grill lids, and playhouse corners weekly. A broom in the morning is all that is needed. June and July: workers take over foraging, the queen stays inside laying, and the colony grows without drawing much attention. Nests are still smallish, and open ones remain a fair DIY target. August and September: peak in Kansas City, when colonies hold their largest worker force and respond fastest to disturbance. This is when hidden ground nests get discovered the hard way, and when sweet foods start attracting company. October and later: numbers fall, and with winter lows averaging 22F the freeze finishes the colony. A remote nest at this point can simply be left to end on its own.
When is a wasp nest actually an emergency
Most nests are a chore. A few are urgent, and it is worth being clear about which is which. It is urgent when someone at the address has a known venom allergy, when the nest is at a door, a stair, or a play area that people pass within a few feet of daily, or when wasps are getting into living space through an interior wall or ceiling. It is also urgent when a colony sits in the ground where a mower, a trimmer, or children regularly go. It is not urgent when the nest is high in a tree at the back of the lot, when it is under an eave nobody walks under, or when it is October and the colony is already winding down. The reason to take the urgent category seriously is that the CDC counted 788 deaths from hornet, wasp, and bee stings in the United States between 2011 and 2021, an average of about 72 a year. That is small against the population and very large against the alternative of moving a nest situation up a week.
What a good first visit includes
The first visit tells you whether you hired the right company, and the tell is how much of it happens before anything gets sprayed. A thorough technician walks the whole property rather than going straight to the nest you reported. Two or three colonies on one lot is common when there is a shed, a fence line, and mature trees. They should ask which doors get used, where children and pets spend time, and whether anyone has a sting allergy, because those answers set the order of work. For a hidden colony, watching flight lines from a distance is the real work. The opening wasps use is frequently several feet from the spot you assumed, and treating the wrong gap accomplishes nothing. Expect dusk or after-dark treatment on ground and wall nests, or a scheduled return for it. Before anyone leaves, you should know which nest was treated, what product went in, how long until activity stops, and who is closing the entrance afterward.
Reading two quotes that do not match
Quotes for the same nest can differ a lot, and the gap almost always comes down to scope rather than one company overcharging. Ask each one to say plainly whether the number covers killing the colony only, or also removing the paper, or also closing the opening the wasps used. Those are three jobs. A cheap quote that ends at step one is not dishonest, it is just smaller, and you will pay the difference later when a new queen finds the same gap next May. Ask what happens if wasps are still active in a week. A colony deep in a wall sometimes needs a second application, and you want the answer to that before you choose, not after. Ask about timing too. A company that will only come at midday for a ground nest is offering worse work than one that schedules at dusk, because the foragers out of the nest in daylight are the ones that come home to a treated entrance and go looking for whoever is nearby.
Prevention that fits a house with a yard and a fence
Most of the wasp problems on a detached Kansas City lot come back to the same handful of openings, and closing them in early spring is worth more than anything you can spray in August. Start at the roofline. Where soffit meets brick or siding, where fascia has pulled loose, and where a gable vent screen has torn are the classic ways a colony gets inside a wall. Fix those in March and April, before a queen has chosen. Then the yard structures. Wooden fences, sheds, and detached garages give both shelter and building material, since paper wasps rasp weathered wood into pulp. Sealing or painting exposed fence tops takes away part of that supply, and a quick look along the top rail each week in spring catches new combs. Finally the ground. Old rodent burrows against a foundation or under a shed are prime yellowjacket real estate. Fill them while they are empty. Once there is traffic at the hole, filling it is exactly the wrong move.