Rodent Control in the Barn: Roll Up the Welcome Mat!

One thing they are, however, is prolific.

Mice reach sexual maturity at about four weeks of age and breed year-round. One female mouse can have five to 10 litters per year, with each litter containing five to six babies. Rats are sexually mature at about six weeks of age; females come into heat every four to five days, year-round, if not bred. Female rats can have four to six litters annually, with four to six babies in each litter. With such impressive reproduction rates, it’s easy to see how a couple of rodents can rapidly multiply into dozens.

Rodents contaminate water and feed sources with their feces and urine. They can transmit disease and carry organisms and parasites, such as fleas, that also spread disease. Rodents can cause damage to structures by chewing on building materials, as well as by tunneling under foundations. Mice can inadvertently create fire hazards when they chew on wiring and make nests inside electrical appliances.

Got Rodents?

Rats and mice aren’t tidy. If they’re living in your barn, you’ll know it.

Mice reach sexual maturity at about four weeks of age and breed year-round.

“Droppings are the biggest clue that you have rodents in the barn,” says Sean Carruth, vice president of Critter Control, Inc., a prominent nuisance wildlife control company founded in 1983 that now has 120 locations in North America.

Other signs include gnawed wires and chew marks on doors, ledges, and corners, footprints in dusty areas, and rub marks (also known as smudge marks), along walls, pipes, and rafters. These dark marks are left by oil and dirt in the rodents’ coats as they travel along frequently used paths.

Carruth explains that rodents often chew on wiring and wood, not for the taste, but to wear down their front incisors, which grow continually.

Roll Up the Welcome Mat

Rodent control in a barn requires diligent management. If mice and rats find an easy source of food and shelter, they’ll make themselves right at home. Roll up the rodent welcome mat by following these strategies.

Feed Storage:

Grain and seeds are preferred food sources for rats and mice. Paper and plastic grain bags are no deterrent to voracious rodents, who will happily chew right through them. The same goes for plastic and wooden bins. Store grain in rodent-proof metal bins with tight-fitting lids. Large metal trash cans make effective grain containers as long as the lids are tight.

On some farms, it’s common practice to distribute feed in a wheelbarrow or large wheeled cart. This may be convenient, but when even a few morsels are left, this is an open invitation to rodents, especially if feed is exposed and left out overnight. If you use this method, be sure to completely empty the container after each feeding.

Horse & Barn Areas:

Many horses are sloppy eaters and that spilled grain in the stalls might as well be a flashing neon sign: “Attention, rodents! Dinner time!”

Check stalls daily and sweep up any spilled feed. Dispose of it in a tightly sealed metal trash container. Don’t just toss the sweepings outside the barn.

Rats and mice like dark, damp areas, so make sure your barn aisle, stalls and storage areas are well-drained and well-lit. Keep garbage cans lidded and empty them frequently.

Don’t stack fence boards, lumber or firewood near the barn, as this offers shelter to rodents. Keep weeds and tall grass mowed around structures.

Tack Room:

You may not have any food items in the tack room, but rodents consider your horse blankets and saddle pads a delightful source of nesting material. Many a disgruntled horse owner has pulled a favorite blanket off the tack room shelf, only to discover industrious rodents have chewed holes in it.

Keep blankets, pads, leg wraps and bandages in tightly-sealed containers. Make sure they are clean and completely dry before storing.

Trapping & Baiting

When you have an established rodent population, you’ll likely have to employ baiting and trapping, in addition to the management practices mentioned.

Old-fashioned “snap traps” are humane in that they kill instantly. They’re inexpensive and easy to use. Snap traps offer an effective, non-toxic method of killing rodents, but in order to catch rats and mice, you have to think like a rodent.

“Rats like to keep one side of their body along the wall, so you need to place (snap) traps perpendicular to the wall,” notes Carruth.

If you use “tunnel” traps, place them lengthwise against the wall to encourage rodents to enter the traps.

You might need to get more creative than cheese as bait. Mice have proven to be partial to marshmallows, peanut butter, chocolate candy, bacon, butter and nutmeats.

When using rodenticide bait, follow label directions exactly as bait must be placed strategically to be most effective. It should also be kept out of reach of children and non-target animals, such as curious barn cats and dogs.

Carruth recommends rodent bait stations as an ongoing control method in barns and livestock housing areas. Rodents enter the holes in the station, consume the bait, leave and die, typically in their burrows. Read bait label directions carefully and replace bait periodically so it remains fresh. Moldy, insect-infested bait isn’t appetizing to the rodents you’re trying to attract.

“Most rodents will die in their burrows, but if you find a dead rodent, use a glove to pick it up by the tail and dispose of it,” says Carruth.

You’ll have the best results keeping rodents out of the barn by following good sanitation practices, targeted trapping and, when necessary, a baiting program. Just remember, rats and mice are simply looking for shelter and an ongoing supply of food. Take these away and those pesky rodents will pack their bags and head for another place to call home.