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Mice & Rats in Delaware
Move inside as nights cool. Droppings and gnawing are the first signs.
| Peak season | Oct – Feb |
|---|---|
| Size | Mouse 3 inches; rat 7 – 10 inches (body) |
| Risk | Health and property — contamination, chewed wiring |
| Who treats it | Mosquito & Pest Authority (sponsor) |
How to identify them
House mice are small and gray with large ears. Norway rats are heavier and brown with a blunt nose. Droppings, grease marks and gnawed packaging are the usual clues.
Mice & Rats in Delaware
Fall harvest and the first cold nights push rodents from fields and woods into Delaware homes, garages and outbuildings, especially in Kent and Sussex farm country.
When they’re active
Swipe to see all 12 months →
What you can do now
- Seal gaps around pipes and doors; a mouse fits through a hole the size of a dime.
- Store food, birdseed and pet food in sealed containers.
- Snap traps along walls work better than poison inside the home.
When to call a pro
Call a pro if you hear activity in walls or the attic, find rat droppings, or keep catching mice after a week of trapping.
Mice & Rats: common questions
Why do I have mice in the house in fall?
Cooler nights push mice from fields and woods into warmer places, and a mouse can fit through a hole about the size of a dime. Sealing gaps around pipes, doors and vents helps keep them out.
Are snap traps or poison better inside the home?
Snap traps along walls are commonly recommended over poison indoors. Poison can lead to rodents dying inside walls, and it can be a risk for pets and children.
What do rodent droppings mean for my health?
Droppings can carry germs, so avoid sweeping them dry or breathing the dust. Wear gloves, wet the area with disinfectant before cleaning, and see your doctor with any health concerns.
Where in Delaware
Where mice & rats rank on each county’s top-pest list:
- New Castle County Top concern
- Kent County Top concern
- Sussex County Not in the county top six
Towns where mice & rats are on the local top-pest list: