A homeowner in Phoenix deals with bark scorpions and fire ants. A homeowner in Seattle deals with carpenter ants and slugs. Same country, completely different pest realities. Here are the top pest threats for each region in 2026, shaped by this year's climate patterns and ongoing invasive species pressures.
For month-by-month pest activity in your specific area, check our Pest Season Calendar or sign up for ZIP-code pest alerts.
1. Blacklegged ticks / Lyme disease — The Northeast remains the epicenter of Lyme disease. Expanding nymph season and growing deer populations are driving record case counts.
2. Brown marmorated stink bugs — Fall invasions continue to intensify in the mid-Atlantic and New England as populations expand.
3. Eastern subterranean termites — Active from southern NJ through PA and south. Warmer winters are pushing the risk zone northward.
4. House mice — Dense housing and cold winters make the Northeast a chronic rodent hotspot.
5. Carpenter ants — Moisture from snow and rain in older homes creates ideal conditions. Peak activity March–June.
1. Red imported fire ants — 320+ million acres infested. Year-round activity in the deep South. The only effective approach is the Texas Two-Step method.
2. German cockroaches — High humidity and dense housing create ideal conditions. Resistance to gel baits is emerging in some metro areas.
3. Formosan termites — The most destructive termite species on Earth. Supercolonies of 10+ million workers devastate structures in coastal cities from Houston to Charleston.
4. Mosquitoes (Aedes, Culex) — Year-round in Florida, 8–10 month season elsewhere. Asian tiger mosquitoes are the dominant daytime biter.
5. Brown recluse spiders — Established throughout the interior Southeast. Often found in storage areas, cardboard, and undisturbed spaces.
1. Stink bugs and Asian lady beetles — The Midwest's agricultural landscape and cold winters create massive fall invasion pressure.
2. House mice — Cold winters drive mice indoors October through March. Prairie-edge homes are especially vulnerable.
3. Carpenter ants — Wet springs and older wood-frame homes. Satellite colonies often enter from trees touching the structure.
4. Japanese beetles and white grubs — Adults skeletonize ornamental plants; larvae destroy turf. June–August peak.
5. Blacklegged ticks — Lyme disease has expanded significantly into the upper Midwest. Wisconsin and Minnesota are now high-risk states.
1. Arizona bark scorpions — The only medically dangerous US scorpion. Found inside homes, in shoes, in bedding. Scorpion-proofing is essential.
2. Fire ants — Expanding westward into irrigated landscapes in Arizona and New Mexico.
3. Roof rats — Thriving in Phoenix, Las Vegas, and irrigated urban landscapes with citrus and palm trees.
4. Kissing bugs (Chagas disease vectors) — Established across the Southwest. Most bites occur when bugs enter homes attracted to lights.
5. Subterranean and drywood termites — Both types are active. Desert doesn't mean termite-free — irrigated landscaping creates localized moisture that supports colonies.
PNW top threats: Carpenter ants (moisture-rich climate is ideal), slugs (year-round in western WA/OR), mice, and cluster flies in rural areas.
California top threats: Roof rats (coastal cities), Argentine ants (the dominant ant species — supercolonies stretching hundreds of miles), drywood termites (fumigation capital of the US), German cockroaches, and bed bugs in urban areas.