Common Household Standing-Water Sources That Breed Mosquitoes

Once a week, walk the property and empty, scrub, turn over, cover, or throw out anything holding water: buckets, plant-pot saucers, kids' pools, toys, folded tarps, trash-can lids, wheelbarrows, unused flowerpots, and neglected recycling bins. Scrubbing matters as much as dumping, because mosquito eggs — especially from Aedes species — are glued to container walls above the waterline and survive a simple pour-out; a brush physically removes them. The weekly cadence isn't arbitrary: it's set by how quickly the egg-to-adult cycle can complete once water is present.

Clogged rain gutters are one of the most overlooked residential mosquito factories — leaf debris dams water into stagnant, organic-rich pools that Culex mosquitoes, New Hampshire's primary West Nile vector, prefer. Clear gutters at least twice a year, in spring and fall, and confirm downspouts and corrugated extensions drain fully rather than holding water in low elbows.

Rain barrels, cisterns, and any water-storage container should have tight lids or fine mesh, with holes smaller than an adult mosquito, so females can't reach the surface to lay eggs. Use stored water first and empty barrels between rain events rather than letting them sit full and undisturbed.

For water you can't reasonably dump — an ornamental feature, or a rain barrel you're actively using — an EPA-registered Bti (Bacillus thuringiensis israelensis) larvicide kills mosquito larvae while leaving mammals, birds, and fish unaffected, targeting only the larval stage per its label. Follow the product label for dosing and reapplication interval.