Pest problems on Long Island are seasonal and, for the most part, predictable. The same calls arrive in the same weeks every year, shaped by our coastal humidity, older housing stock and a lot of mature tree cover. If you know what's coming, most of it can be handled before it becomes an infestation.
Here's what each part of the year looks like across Nassau and Suffolk, and what's worth doing ahead of it.
Late winter (February – March): the quiet planning window
Nothing much is active outdoors yet, which is exactly why this is the cheapest time to fix things.
- Overwintering mice are still inside walls and attics. If you heard scratching in January, the entry point is still open.
- Cluster flies and stink bugs wake up on the first warm afternoons and appear at sunny windows — a sign of gaps around attic vents and window frames.
- Foundation and crawl-space repairs are easier to schedule now than in peak season.
Do now: walk the foundation and garage for gaps, replace hardened door sweeps, clear last year's leaf litter from window wells.
Spring (April – May): termites and the first tick wave
Termite swarms. Eastern subterranean termites swarm on warm, humid days after rain, usually mid-March through May. A small pile of identical discarded wings on a windowsill or near a basement slab is the single most common way homeowners discover termites. Older homes in Levittown, Massapequa and Babylon — slab-on-grade and post-war construction with soil contact — see this most often. See termite protection for how treatment and monitoring work.
Ticks. Blacklegged (deer) ticks are active any day above about 40°F, and nymphs — the stage most likely to transmit disease — peak from May into July. Suffolk's wooded edges and tall grass carry the heaviest pressure, but ticks are common in Nassau yards backing onto parkland or preserves too.
Carpenter ants and pavement ants start foraging indoors, typically along kitchen counters and baseboards near a moisture source.
Do now: book a termite inspection if your home is over 30 years old or has any wood-to-soil contact; create a mulch or gravel barrier between lawn and woodline; treat the yard perimeter for ticks before Memorial Day.
Early summer (June – July): mosquitoes and stinging insects
Mosquito pressure builds fast once nighttime temperatures hold above 60°F. Long Island's problem is standing water in small quantities — a clogged gutter, a boat cover, a saucer under a planter, a corrugated extension pipe. Asian tiger mosquitoes breed in containers holding as little as a bottle cap of water and bite during the day, which is why "we only get bitten at dusk" is no longer true here.
Yards near tidal marshland in Babylon, Lindenhurst and along the South Shore also see salt-marsh mosquitoes, which fly considerable distances and can't be solved by source reduction alone. That's where a barrier treatment program earns its keep — details on mosquito control.
Wasps and yellowjackets start building in earnest: paper wasp nests under eaves and deck rails, yellowjackets in wall voids and ground burrows.
Do now: empty or drill anything holding water weekly, clean gutters, knock down small new wasp nests in early June while they're the size of a golf ball.
Late summer (August – September): peak stinging insects and roaches
Yellowjacket colonies reach maximum size in late August, and their diet shifts from protein to sugar — which is why they suddenly show up at barbecues, garbage cans and outdoor bars. Nests in wall voids should never be sealed shut from the outside; blocked workers chew inward through drywall.
Cockroach activity peaks with heat and humidity, particularly German cockroaches in apartments and rentals in Great Neck, Hempstead and the denser Nassau villages, where shared plumbing chases let them move between units. Treating one unit rarely holds if neighbors aren't treated. See cockroach control.
Second tick wave: adult deer ticks pick back up in October, so don't stand down yard protection after Labor Day.
Do now: have accessible wasp nests removed professionally before Labor Day gatherings; fix leaking traps and grout gaps under sinks.
Autumn (October – November): rodent season
This is the busiest month of our year. When overnight lows sit below roughly 50°F for several days running, mice and rats move toward heated structures — all at once. A mouse needs a quarter-inch gap; a rat needs about a half inch.
The usual entry points on Long Island homes:
- Garage door corners where the rubber seal has hardened
- Utility line penetrations at the foundation
- Dryer vents with a broken damper
- Crawl-space vents and settled basement window frames
- Attached-garage-to-house doors without a sweep
Colonial and split-level homes in Commack, Manhasset and the North Shore hamlets often have detached garages and mature landscaping right against the foundation — both make rodent pressure worse.
Bait alone reduces the population already inside; it doesn't stop next year's arrivals. Permanent work means exclusion: copper or stainless mesh, mortar, metal flashing and new sweeps. Steel wool rusts and expanding foam gets chewed through. More on rodent control.
Do now: exclusion work in September or early October, before the temperature drop. Sealing an empty house costs far less than trapping a populated one.
Winter (December – January): what's still active
Cold weather doesn't end pest work — it moves it indoors.
- Mice and rats already inside continue breeding in heated wall voids and attics.
- Bed bugs are entirely indoor and travel with holiday guests and luggage; see bed bug treatment.
- Squirrels and raccoons look for attic denning space; squirrel litters arrive as early as February.
- Stored-product pests appear in pantries with old flour, birdseed and pet food.
Do now: inspect the attic for droppings and chewed insulation, check pantry staples, and inspect luggage and guest bedding after visitors leave.
A simple year-round baseline
Whatever your property, four habits prevent most of what we get called for:
- Keep water away from the house — working gutters, extended downspouts, graded soil.
- Keep a clear band around the foundation — trim shrubs back, move woodpiles and stored bins off the wall.
- Seal on a schedule, not after a sighting — check gaps each spring and fall.
- Deal with the first sighting. One mouse, one wing pile, one small nest is a ten-minute job. A month later it isn't.
Long Island's mix of coastal moisture, older homes and heavy tree cover means pests here behave differently than they do inland, and a treatment plan built for one town's housing stock doesn't always fit another's. If you want to know what's most likely on your street, check your service area or book an inspection — we'll tell you what we're seeing locally this month.