Interactive Tool

February

Still working indoors near heat.

A February thaw brings boxelder bugs and lady beetles out of wall voids. Vacuum, don't crush — crushing stains, and stink bugs earn the name.

Year-round.

March

Swarmers emerge March through July. A colony needs three and a half to four years of maturity before it produces them, so winged carpenter ants indoors means the colony has been there a while.

One or more blacklegged tick life stages may be active in any month in Ohio.

Emerging indoors on warm days.

April

Queens emerge in April and May and start a colony from nothing. A nest found now is a five-minute job; the same nest in September is a project.

Swarmer season. Look for coarse frass like pencil-sharpener shavings, and listen for a dry rustling in walls at night.

Nymphs becoming active.

May

Ohio's mosquito season runs May through October. The main West Nile carrier here is the northern house mosquito, and it's a container breeder: gutters, tarps, buckets, saucers.

Still founding nests. Best month of the year to seal soffit and siding gaps.

Nymphs active. Most infective bites happen June and July.

June

Most infective bites occur between June and July. A rash shows up 3 to 30 days after a bite, and about 30% of confirmed cases never develop one at all.

Building through the season.

Last of the swarmer season.

August

Here's the one that surprises people. From August through October a yellowjacket colony's food preference shifts from proteins to sweets — and by late August it's 4,000 to 5,000 workers strong. Nothing changed about their temperament. The colony hit maximum size and started hunting sugar.

Still at peak case volume.

Peak infection window.

September

Colony size peaks now. This is when most sting calls come in, and when a nest inside a wall void finally makes itself known.

First real cold snap sends boxelder bugs, brown marmorated stink bugs, Asian lady beetles and western conifer seed bugs toward the heat radiating off south- and west-facing walls.

Adults active again through fall.

October

Peak month. OSU's number one recommendation isn't a spray, it's exclusion: caulk window frames, repair door sweeps, screen vents, fix loose siding. The same work keeps mice out.

Calls climb as the weather turns. House mice breed year-round — 3 to 11 young per litter, 18 to 21 day gestation — so a small problem compounds fast.

Adult blacklegged ticks stay active into winter whenever it's above freezing.

November

Prime season. A mouse fits through a dime-sized gap, and older Ohio housing offers plenty.

Settling into wall voids and attics for the winter.

Adults stay active whenever it's above freezing.

December

Established indoors now.

Holiday travel is the vector. Lodging turnover is how they move.

Beginning to forage indoors near heat.