Note: some rodents carry hantavirus, a potentially deadly
infection that is transmitted when humans breathe in dust
contaminated with the body fluids of infected rodents. If you
will be cleaning up after a rodent infestation, read this important information
Trapping rodents is a perfectly acceptable method of control. It
should be done afterrodent prevention
techniques and rodent
proofing is completed. Trapping is especially desirable
when rodenticides cannot be used near food, small children, or
where domestic animals or livestock are present. Traps should be
used indoors to prevent the serious odor and fly problems that
can occur when poisoned rodents die in walls.
Before any trapping, first determine where rodents are
entering structures or where rat activity is occurring.
Bait selection is important for trapping success. Peanut
butter, nuts, bacon, pieces of apple, and moistened oatmeal are
Place traps perpendicular to runways along fence tops and
next to walls. Correct placement of snap traps is crucial to
Pre-baiting traps is an important step. Rats tend
to avoid new objects. Pre-baiting involves placing baited traps
without setting them. This step allows rats and mice to become
familiar with the traps. Place pre-baited traps in areas of rat
activity for a few days.
After a few days, set baited traps
perpendicular (at right angles) to active rat runways where
droppings are seen. Follow manufacturer’s label instructions for
setting traps. Before setting, securely attach bait to the
When the number of animals captured per day declines, check
for fresh droppings. If droppings are still observed, the rodents
may be avoiding the traps. Change trap location to new area of
Repeat the cycle of pre-baiting and trapping until no new signs
of rat activity are seen.
Some rodents can carry Hantavirus or other diseases.
Therefore, when cleaning rodent areas, do not stir up dust by
sweeping and vacuuming droppings, urine, or nesting material.
Using rubber or latex gloves, apply a disinfectant or a 10%
bleach solution onto dead rodents and droppings. Clean up with
paper towels. Double-bag and dispose of waste in a garbage can
with a tight-fitting lid. Afterward, thoroughly wash hands with
soap and water.
Information about rodents and disease can be obtained from the
District laboratory at (650) 344-8592.