Seasonal Rodent Problems in Jacksonville: A Year on the First Coast

Rodents are active in Jacksonville all year. Mild winters let roof rats and house mice keep breeding through most of the year, and UF/IFAS notes a female roof rat can have 4 or 5 litters a year. Calls still tend to rise at certain times: when a winter cold front comes through, when backyard fruit ripens, and during and after hurricane season, when storms flood burrows and damage roofs.

Here is what to watch for through the year and what to check.

Winter: cold snaps and citrus

Jacksonville winters are short and mild, but a hard cold front still sends mice and rats looking for warm shelter. Garages, attics and the space behind kitchen appliances fill up quickly after the first real cold night.

Winter is also citrus season in many backyards. UF/IFAS describes roof rats as very fond of fruit and says hollowed-out fruit is the most common sign of them. Pick up fallen fruit daily and harvest ripe fruit promptly.

Checklist: replace worn garage door seals, check under-sink pipe gaps, pick up fallen citrus.

Spring: nesting and young

Spring brings more young rodents. UF/IFAS says roof rats reach maturity at 3 to 4 months, so the litters from winter are ready to move out and look for their own spots by late spring. You may hear more activity in the attic and see rats on fences and power lines at dusk.

Spring is a good time for a roofline check before summer heat makes attic work harder. Trim palm skirts and tree limbs away from the roof.

Checklist: trim palms and limbs, check soffits and vents, clear yard debris and woodpiles.

Summer: heat and storms

Summer in Jacksonville means heat and afternoon thunderstorms. Hot attics make dead rodents smell fast, so trapping in summer needs daily checks. Heavy rain floods burrows along slabs and creek banks, and Norway rats move up into garages and sheds.

Florida's Department of Health ties leptospirosis exposure to water and soil with urine from infected animals, especially after flooding and heavy rainfall. Wear gloves and boots when cleaning flooded garages and yards.

Checklist: check traps daily, keep garbage lids closed, clean up standing water and debris after storms.

Hurricane season

Atlantic hurricane season runs from June through November. Storms do several things that help rodents get in. Wind lifts soffit panels, tears vent screens and drops limbs on roofs. Flooding forces rats out of burrows. Debris piles at the curb give rats cover for weeks.

After a storm, walk around the house and look up at the soffits, gable vents and roof vents. Get any damage sealed quickly. Follow the city's rules for storm debris and yard waste, and don't leave piles against the house. The trash and property rules guide covers the city's yard waste limits.

Hurricane prep can bring rodents inside too. Patio furniture, potted plants and stored items moved into the garage can carry mice in with them.

Checklist: inspect the roofline after each storm, keep debris away from the house, check items brought in from outside.

Fall: back into the attic

As nights cool in October and November, rodent activity indoors often picks up again. Roof rats that spent summer outside in trees and palms return to attics. Mice move into garages and walls.

Fall is a good time for a full rodent inspection, especially after hurricane season. A technician can check for storm damage and seal gaps before winter.

Checklist: inspect after hurricane season, seal any new gaps, set traps at the first sign of droppings.

Construction and land clearing

Jacksonville keeps growing, especially in Oceanway, Nocatee, the Westside near Oakleaf and the edges of St. Johns County. When woods and fields are cleared for a new phase, the rodents living there move to the nearest cover, which is often the finished homes and garages next door.

If land is being cleared near you, check your house before the bulldozers arrive: garage door seals, vents and line penetrations. Keep pet food and seed sealed, and watch for droppings in the garage for a few weeks after the clearing.

Year-round habits

Some things matter in every season:

• Store pet food and birdseed in sealed metal or heavy plastic bins
• Keep garbage cart lids closed and follow the city's set-out times
• Keep palms trimmed and limbs back from the roof
• Keep firewood, lumber and debris off the ground and away from the house
• Check traps daily if you are trapping

If you are dealing with an active problem now, start with rat control or mouse control.

Common questions

Related reading

• Rats in palm trees
• Roof rats
• Exclusion and Sealing
• Rodent diseases in Florida