How Do I Get Rid of Rats Under a Deck?

Norway rat burrow openings are typically 2–4 inches across, smooth-edged, and often have fan-shaped excavated soil at the entrance, with tunnels running about 18 inches deep and escape 'bolt holes' nearby. Confirm which burrows are actively used by loosely plugging entrances with newspaper or grass and rechecking in 24–48 hours — displaced plugs mean a live burrow, undisturbed ones likely mean it's abandoned.

Pre-bait unset snap traps for two to three days near burrow entrances and travel routes, since Norway rats are neophobic and avoid new objects at first. Then set them. Skip poison here — a poisoned rat that dies underneath a deck decays in an inaccessible spot, creating an odor problem and a secondary-poisoning risk to any pet or wildlife that finds the carcass.

Dig a trench about 12 inches deep along the deck's perimeter and install ¼-inch galvanized hardware cloth — not chicken wire, which rats can chew through. Bend the buried portion outward into an L-shape pointing away from the deck, which stops rats from simply digging under the vertical barrier. Backfilling the trench with loose stone adds another layer of digging discouragement.

Trim the bottom foot of vegetation around the deck, clear clutter and woodpiles that provide cover, and eliminate food sources like fallen fruit, open compost, and accessible pet food. Recheck the barrier yearly, especially after freeze-thaw cycles that can shift buried mesh.