Controlling Rodents Around Swine Barns

Brian Cotton, Swine Specialist, Brandon

Rats and mice can be a major threat around swine buildings. They consume and contaminate feed, damage walls and building foundations, and have been implicated in maintaining or spreading disease.

When present in relatively high numbers, rats and mice can occasionally be seen during daylight hours. They are most active at night, particularly just after dusk. Conducting an inspection of the premises at dusk may assist in identifying the location, distribution, and severity of a rodent infestation.

Rats and mice can climb any rough vertical surface. Rats can jump up to 36 inches (approx. 1 m) and can squeeze through openings slightly larger than ½ inch (1.2 cm) across. Mice can jump 12 inches (30 cm) and squeeze through a 3/8 inch (1 cm) opening or less.

Rodent control should incorporate sanitation, rodent-proof construction and population reduction. The first two are preventive measures. Reduction techniques include trapping, toxic baits or fumigation. Recording trapping success will help determine the need for further control efforts.

Sanitation: Although good sanitation will seldom eliminate rodents, it will aid in controlling them. Storing feed in steel feed bins, removing weeds and debris from around farm buildings, and keeping a 2-3 foot, (0.6-1.0 m), weed-free strip around buildings will discourage rodents.

New buildings should be constructed with materials that will be hard to damage by rodents. A common entry point for mice into buildings is the unprotected end of corrugated or ribbed metal siding. These openings should be blocked with mortar or metal.

Rats can be discouraged from burrowing near foundations by laying a strip of coarse (1 inch) gravel in a 2 foot wide by 6 inch (60*15 cm) deep band around the foundation. A buried curtain of ¼ inch to ½ inch mesh extending 12 inches to 18 inches (30-45 cm) downward and outward to 12 inches (30 cm) from the foundation will help prevent rats from burrowing under the foundation.

Trapping and toxic baits are two of the most common methods of reducing rodent populations. A variety of sticky traps, snap traps, multiple live traps, etc. are available and should be placed in high infestation areas. These can be monitored for success daily and kept clean. Sticky glue board traps lose their effectiveness in dusty areas.

Toxic baits (rodenticides) come in a variety of brands and packaging. These must be placed where pigs or other domestic animals will not get into them. Rats tend to feed in one or two locations. Mice nibble at food here and there along their path.

Baits and traps should be located in secluded areas along walls where rats and mice tend to feed.

Fumigants should be used only by licensed pest control operators.

Once rodent control has been achieved, an ongoing control program needs to be maintained.


  1. Eliminate or reduce the number of places rodents can use for shelter. Prevent clutter in and around buildings, and keep stored feed in rodent-proof facilities. Where practical, make structures rodent-proof. When rodents have no place to hide or nest, they cannot thrive.
  2. If rodents or evidence of rodents are present, begin or increase control efforts. Use traps or rodenticides to reduce their numbers. Place baits or traps in areas where rodents are active, and maintain control efforts diligently until successful.
  3. Once rodent numbers have been reduced, continue a regular program of control to keep rodent numbers to a minimum. Maintain permanent bait stations or traps to control invading rodents and keep surviving rodents from multiplying.