The half of the job that lasts.
Trapping removes the rodents already inside. Sealing decides whether more can follow. A building with open gaps is like a house with its door ajar, and the next rodent finds it as easily as the last.
The CDC's guidance on keeping rodents out follows the same sequence of sealing up, trapping out and cleaning up. Closing openings is the opening step and the one that holds the longest.
Where rodents get in.
A mouse can use a gap about as wide as a pencil, and a rat needs roughly double. Most buildings have dozens of openings that size, and they gather in predictable spots.
| Opening. | Material. | Notes. |
|---|---|---|
| Roof edge and soffit. | Metal flashing and mesh. | Check where fronds or limbs touch the roof. |
| Vent covers and screens. | Heavy mesh or metal caps. | Salt air can corrode thin screens. |
| Pipe and cable entries. | Steel mesh and sealant. | Often hidden below cabinets and in garages. |
| Garage door corners and sweeps. | New seal or threshold. | A worn seal can leave a finger-wide gap. |
| Foundation vents and skirting. | Metal screen. | Look for torn or missing covers after storms. |
Coastal wear over the seasons.
Salty, damp air is rough on a building. Screens corrode, trim swells, sealant cracks and storms can loosen covers. A short check of vents and seals after each wet season finds new gaps before an animal does.
Trim any frond or branch that touches the roof, since it acts as a bridge. The technician marks every contact point and says which ones to cut back.
How the work goes.
- Survey the whole exterior and record every opening.
- Confirm the animals are out before covering any hole.
- Cover gaps with metal or mesh, then set sealant to hold it.
- Photograph each repair and recheck after a few days.
Sealing with animals still inside can leave them trapped in a wall, which brings noise and odor. That is why trapping comes first, as the trapping page explains.
After the entries are shut.
With the openings shut, soiled areas can finally be cleaned. Cleanup of the attic or crawl space and damage repair pick up from there, or start with an inspection to learn what needs sealing.
While you wait for a technician: do this, skip that
Thinking of tidying before the visit? Take the steps in order, and pause at any that seems unclear.
- Brushing dry droppings flings fine particles toward your face, so the broom stays put.
- Open every door and window that will open, then wait thirty minutes before starting.
- Gloves protect you during the job and soap protects you after it.
- Wet it all thoroughly, wait roughly five minutes, then pick the waste up with towels meant for the trash.
- Knot the bag and set it with ordinary household trash, and never lift a carcass with bare fingers.
- Fever, aches or breathlessness after contact with waste belong at a clinic, not with an exterminator.
Where the safety steps come from
Prefer the original guidelines? Their titles and links appear below.
- CDC steps for preventing hantavirus exposure: The source of the sealing and tidying suggestions made on this page.
- CDC advice on cleaning rodent droppings and nests: Ventilate, soak, bag: the order of work the CDC lays out.