The Complete Guide to Wasp and Hornet Control

Paper wasp nests are open and umbrella-shaped, with visible hexagonal cells facing downward, hung by a single stalk under an eave, deck rail, mailbox, or grill cover. You can see the wasps walking on the comb, and the colony is small (15 to 100 workers).

Yellowjacket nests are concealed inside a void: a wall cavity, a soffit, an attic corner, an old rodent burrow, or under a deck. You see a steady stream of insects entering and leaving a single hole, but no comb is visible. Treatment is completely different, and confusing the two is the most common cause of multi-sting incidents.

The first six weeks of the season (roughly March to mid-May in most of the country) is the cheapest, safest treatment window. A queen alone or a colony of 5 to 10 workers will tolerate a person standing close to the nest, and a single contact aerosol from a long pole resolves the problem in seconds.

Treatment difficulty roughly doubles every three to four weeks through summer. The same nest in late August has 200 workers, alarm pheromones tuned to vibration, and a defensive radius of 15 to 20 feet. Push every treatment decision toward the front of the calendar whenever you can.

Sealed yellowjackets do not die quietly. They chew through drywall and emerge inside the house, often in a bedroom or kitchen, which turns a wall-void problem into an indoor swarm.

The correct sequence is to treat the void with a labeled insecticidal dust first, wait at least seven full days for the colony to die, and then seal the entry. Always in that order. This is one of the most common reasons yellowjacket calls become emergency calls.

Only in the very early season, when a queen-only nest is the size of a quarter and contains one or two wasps. In that window, a calm afternoon approach with a long pole is fine.

Once a paper wasp nest has 10 or more workers, day treatment is risky because foragers are actively defending. Wait until full dark (ideally between 10 PM and dawn) when ambient temperature is below 70 degrees and all foragers are home. Use a flashlight with a red film over the bulb because white light agitates wasps at night.

Trap-catch traps lower ambient yellowjacket pressure across a yard but rarely solve an active nest by themselves. They are most useful in spring, when newly emerged queens are searching for nest sites, and in fall, when foragers shift to sugar and crash picnics.

Hung along a property perimeter from April through October, traps intercept overwintered queens and late-season foragers and noticeably reduce the number of nests that establish on the structure. Treat them as a prevention tool, not a treatment tool.

No. Mud daubers are solitary, non-aggressive wasps that hunt and paralyze spiders to feed their young. They almost never sting a person, and the small mud tubes they build on walls and ceilings cause no structural damage.

Knock down empty mud cells in winter once activity has stopped, and otherwise leave them alone. They are net-beneficial in a yard because they reduce spider populations on their own.

No. The entire visible nest dies with the first hard frost, and only newly mated queens survive winter, in sheltered spots away from the nest itself. A nest you find in a soffit in October will not be active again next April.

Queens often pick the same general structure to start a fresh nest the following spring, however, which is why winter is the right time to seal soffit gaps, eave cracks, and siding penetrations. An empty nest in February is the safest nest you will ever handle, and removing it removes the residual queen pheromone that attracts next year's start.