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Introduction

Rodent pests are defined as “commensal” because they live in close association with people. When food, water and shelter are available, we have made a perfect environment for rodents (and other pests).

Food availability

Rodents feed on food items that we grow, harvest, process, store, and discard. Problems exist if people have inadvertently provided a nearby food source, ranging from fresh produce to food and even pet waste.

Photo shows a large boulder surrounded by a few landscape plants and some areas of bare soil. On top of the boulder is a depression where water collected and a rat is drinking from the water.
Some water sources are not obvious.

Water availability

Norway rats need to drink standing water every day. Water can be found in puddles or condensation on a pipe.

Mice will drink water too, but can obtain enough moisture from most food sources to remain hydrated.

Nest site availability

Norway rats prefer to burrow in soil, but will take advantage of voids near a food source. Mice can make nests inside walls, equipment, and other protected places.

Photo of a hole leading into the soil under a bush
Rat burrows indicate that steps need to be taken to seal openings into buildings and reduce outdoor access to food.
Photo shows several paper boxes on a metal rack. In the center of a photo, the handle of the box has been enlarged and brown staining from rodent sebum is present below the opening.
Rats were nesting in this and other file boxes that were undisturbed near a reliable food source.