Pest calendar, month by month
On the South Shore, every pest has its season, and most problems are solved by acting a month early. This calendar shows what is active each month and the useful step at that moment. Peak periods come from this site's own pest pages; the monthly step is a practical reminder, not an offer of service.
January
What is active
This month's step
Mice that came in last fall are moving inside the walls: trap and seal, do not wait. Listen for attic noise too, a sign of squirrels.
February
What is active
This month's step
Squirrels look for a place to give birth in attics. Inspect the roof, soffits and vents before a hole gets chewed.
March
What is active
- Asian lady beetles in March
- Cockroaches in March
- Flies in March
- Groundhogs in March
- Pigeons and birds in March
- Raccoons in March
- Rats in March
- Silverfish in March
- Skunks in March
- Squirrels in March
This month's step
Groundhogs come out of hibernation hungry, and raccoons give birth in April or May: never seal an entry without checking for young first.
April
What is active
- Asian lady beetles in April
- Carpenter ants in April
- Cockroaches in April
- Flies in April
- Groundhogs in April
- Pigeons and birds in April
- Raccoons in April
- Rats in April
- Silverfish in April
- Skunks in April
- Sowbugs and centipedes in April
- Squirrels in April
- Ticks in April
This month's step
Carpenter ants become active again: fine sawdust, winged ants indoors. Trim branches touching the roof and move firewood away from the foundation.
May
What is active
- Bats in May
- Bees and bumblebees in May
- Carpenter ants in May
- Cockroaches in May
- Groundhogs in May
- Mosquitoes in May
- Pigeons and birds in May
- Raccoons in May
- Rats in May
- Silverfish in May
- Skunks in May
- Sowbugs and centipedes in May
- Squirrels in May
- Ticks in May
This month's step
Wasp queens start their nests, still small and easy to remove. Tick season starts at the edge of woodlots; skunk kits arrive toward the end of the month.
June
What is active
- Bats in June
- Bed bugs in June
- Bees and bumblebees in June
- Carpenter ants in June
- Cockroaches in June
- Earwigs in June
- Groundhogs in June
- Mosquitoes in June
- Pigeons and birds in June
- Raccoons in June
- Silverfish in June
- Skunks in June
- Sowbugs and centipedes in June
- Ticks in June
- Wasps and hornets in June
This month's step
Wasps growing, mosquitoes after rain, ticks in tall grass. Empty standing water once a week. No bat exclusion: the pups cannot fly.
July
What is active
- Bats in July
- Bed bugs in July
- Bees and bumblebees in July
- Carpenter ants in July
- Cockroaches in July
- Earwigs in July
- Fleas in July
- Flies in July
- Groundhogs in July
- Mosquitoes in July
- Pigeons and birds in July
- Raccoons in July
- Silverfish in July
- Skunks in July
- Ticks in July
- Wasps and hornets in July
This month's step
July 1 moving day: inspect furniture and mattresses before carrying them in. Wasp nests become visible and mosquitoes follow the storms.
August
What is active
- Bats in August
- Bed bugs in August
- Bees and bumblebees in August
- Cockroaches in August
- Earwigs in August
- Fleas in August
- Flies in August
- Groundhogs in August
- Mosquitoes in August
- Pigeons and birds in August
- Raccoons in August
- Silverfish in August
- Skunks in August
- Sowbugs and centipedes in August
- Spiders in August
- Squirrels in August
- Ticks in August
- Wasps and hornets in August
This month's step
Sealing month: gaps on south and west walls, soffits, window frames, before lady beetles and cluster flies. Wasp nests are at their peak.
September
What is active
- Asian lady beetles in September
- Bats in September
- Bed bugs in September
- Cockroaches in September
- Earwigs in September
- Fleas in September
- Flies in September
- Groundhogs in September
- Mice in September
- Mosquitoes in September
- Raccoons in September
- Rats in September
- Silverfish in September
- Skunks in September
- Sowbugs and centipedes in September
- Spiders in September
- Squirrels in September
- Ticks in September
- Wasps and hornets in September
This month's step
Seal mouse entry points before the first cold nights. Watch for bat exits at dusk to prepare a fall exclusion.
October
What is active
- Asian lady beetles in October
- Bats in October
- Cockroaches in October
- Fleas in October
- Flies in October
- Mice in October
- Rats in October
- Silverfish in October
- Skunks in October
- Sowbugs and centipedes in October
- Spiders in October
- Squirrels in October
- Ticks in October
This month's step
Asian lady beetles and cluster flies on sunny walls, mice in foundations, squirrels looking for an attic. The recommended window for bat exclusion.
November
What is active
- Asian lady beetles in November
- Cockroaches in November
- Flies in November
- Mice in November
- Rats in November
- Silverfish in November
- Squirrels in November
- Ticks in November
This month's step
Last sealing before winter. Wasp nests are abandoned and can be removed safely. Mice that have not found a way in are still looking.
December
What is active
This month's step
Mice in walls and pantries, squirrels in the attic. Coming back from holiday travel, inspect the luggage: a classic way bed bugs arrive.