Critter Control

Appreciating wildlife is fine, and horse people generally are wildlife lovers. However, when nature's creatures take up residence in your barns, sheds, or fields, they can bring disease and destruction. It's imperative to the health of humans, horses, and pets that you evict and prevent the return of these unwanted creatures to your horse's habitat.

Rat Patrol

At the top of the barn pest list are rats and mice.

"The Norway rat and other rat and mouse species carry fleas and flea diseases," says Candace Cummings, Wildlife Associate-Urban Specialist, Clemson University. "They gnaw on the barn structures and food containers, consume grain and feed, leave fecal contamination in food and tack, and build nests, burrows, and tunnels above and below ground. Notes horse owner Judith L. Lessard, Editorial Assistant of Publications and Media Relations at the College of Veterinary Medicine at Michigan State University, "Mice can make nests in a secluded area in the tack or grain room, such as on the seat of a saddle that is covered up with a saddle blanket or under the saddle. They use bits of material that they've been able to chew up and drag to that area such as paper from grain bags or bits of cloth from rags you have laying around."

Small, persistent, and clever opportunists, rats and mice gain entry into stalls, tack, and feed rooms by gnawing, climbing, jumping, swimming, and other tactics, Cummings says. "They are constantly exploring their surroundings, memorizing the locations of pathways, obstacles, food, water, escape routes, and other elements of their domain. They quickly detect and avoid new objects placed into their familiar environment. Thus, objects such as traps and poison bait are often avoided for several days."

The first line of defense in a rat/mouse control program is to eliminate their food sources. "Good sanitation practices are very important," Cummings emphasizes. "Clean up spilled feed and grain. Store feed in rodent-proof containers--metal garbage cans work best. Stack feed containers off of the ground on pallets." Paint a 12-inch wide band on the floor around the perimeter of feed and tack rooms to make rodent signs easier to spot.

Rats need fresh water daily, so eliminate water sources by repairing all leaky pipes and removing containers where water can accumulate outside. "Keep water buckets off of ground level and, if possible, surround the water bucket area with sheet metal to prevent rats from climbing into buckets," recommends Cummings.

Seal all points where rats and mice enter buildings. "Hardware cloth can be used over large holes and entrances where rats are gaining access, and steel wool can tem porarily plug holes," Cummings says. "Sheet metal bands 18 inches wide can be attached to the outside of barn walls 36 inches above ground level or 30 inches above where a rat can jump to prevent rats from climbing up outside walls and entering the barn through the roof or windows."

Cummings also recommends placing a two-foot wide band of one-inch diameter gravel a half-foot deep around the perimeter of the barn to deter burrowing.

Finally, eradicate rats and mice through poisoning. "It is important to use only poisons labeled for the species you want to control," Cummings emphasizes. "Anticoagulant poison baits are labeled for use on Norway rats. They are quite acceptable for rats, do not cause bait 'shyness' (when a rat consumes only enough poison bait to make himself sick, at which point he will avoid offerings of any new poison bait item), are easy to apply, and if used properly, are relatively safe to use around livestock, pets, and humans. Anticoagulant baits include Ramick Green, Final, and Rozol. These can be found at most feed/seed or farm supply stores. Pelleted forms work best, and multiple feedings of the bait are required to cause death of the rat. To work best, several feedings should occur over a 10-day period." Carefully follow label instructions.

Place rat baits at bait stations throughout the barn, within 20-30 feet of one another. "Bait stations should be large enough to allow several rodents to feed at once and to have at least two openings," Cummings instructs. "Rats will not visit bait stations if they are not conveniently located where rodents are active. Place stations between the rats' shelter and food supply, near rat burrows, against walls, or along their travel routes. Bait stations can be as simple as a flat board nailed at an angle to the bottom of a wall or a length of pipe into which the bait can be placed. Never place bait stations where they can be knocked over. Do not allow pets and children to roam freely unattended when baits are present."

For barns that are not rodent-proof, permanent bait stations might be in order. States Cummings, "Stations can be placed inside buildings, along the outside of building foundations, or along the perimeter. Bait stations will keep rodent populations relatively low when maintained with fresh bait. Rodents moving in from nearby areas will be controlled before they can reproduce and cause damage."

Baits must always be fresh, so you should check stations and keep them filled with fresh bait at all times for 10-15 days. Dispose of any uneaten bait in accordance with the label. "Since rats are very suspicious, it may take several days for them to enter and feed on the baits," Cummings says.

Peril Up Above

Although bird watching is a popular hobby throughout the world, it's not a fun sport in the barn. Notes Lessard, "Starlings and the English (house) sparrow are annoying. They defecate all over everything--hay, straw, even in the water buckets and watering trough, contaminating the water."

Birds and bats are attracted to the barn's warm, dry roosting sites high in the rafters. Birds also enjoy nibbling on spilled grain. Primary offenders are house sparrows, blackbirds, grackles, starlings, and pigeons.

Besides the mess, birds are a significant source of disease that can affect horses, humans, and other pets. Explains Tom Barnes, PhD, Department of Forestry at the University of Kentucky, "Birds are associated with histoplasmosis (a respiratory disease) and salmonella." These diseases are spread by inhaling spores released from dried bird and bat feces. "If you disturb a pile of dried guano (feces), you've just released billions of spores," Barnes states. "The birds themselves can release the spores by disturbing the guano."

Prevent birds and bats from settling into potential roosting sites by installing plastic bird netting below the rafters or ceiling, Barnes suggests. Also, remove or knock down their nests. "Other deterrents include sticky repellents or sharp little metal spikes to discourage or prevent birds from landing on those areas," Barnes says. "As a last resort, there are poisons for birds."

Until your bird/bat eviction is successful, be sure to wash away fresh guano each day and not let it build up, Barnes notes. When cleaning up dried guano, wear a respiratory mask and remove the animals from the barn for a few hours in order to avoid inhalation of released spores.

Larger Aggravations

Opossum, raccoons, and skunks are not averse to making forays into the barn in search of food or nesting sites.

"Horse barns and horse farms create an ideal habitat for these animals," says Barnes. They carry and spread a variety of diseases to other animals and humans via fecal or urine contamination of food or water supplies, shedding of parasites into the environment, or through bites.

"Most commonly, these animals carry rabies, leptospirosis, and a number of different parasites. Raccoons, which are common around barns, can also carry canine distemper and parvovirus, which can affect unvaccinated dogs." Opossums, skunks, and armadillos have also been identified in spreading equine protozoal myeloencephalitis (EPM).

These animals also can cause problems in the barn. Notes Lessard, "Unless your grain cans are securely closed and somehow locked against their prying little feet, raccoons can get into them and make a huge mess by dumping over the grain cans and spilling the contents. Raccoons can be vicious fighters and can do a lot of damage to the farm dog."

Barnes says the best way to eradicate animals is with trapping and removing. "They are easy to trap and there are companies that specialize in wildlife." Do-it-yourselfers should check with their state's game protectors or game wardens (Division of Wildlife, Department of Natural Resources) concerning live or kill trapping methods, the best types of bait, placement of traps, safety issues involving other pets, and laws governing protection and how and where trapped animals can be released. Your county cooperative extension agent also can give advice or provide contact numbers for the state game protector's office.

Wherever these animals are considered game animals, they can be shot in accordance with local wildlife and firearm laws.

Keep animals from invading the barn by repairing holes and tunnels that provide entry or habitats, and by cutting off their food sources, says Barnes.

Wholly Unacceptable

Woodchucks can carry rabies, but their tunneling habits are what make woodchucks and other burrowing animals a big no-no on the horse farm. Says Lessard, "Woodchucks dig holes in pastures, which can be very dangerous for a horse...But woodchucks can also burrow under cement floors in barns or hay storage areas, and eventually that expensive cement floor can crack or collapse, especially if a lot of weight--tractors, tons of hay, etc.--is put on it."

The primary method of removal is via live or kill trapping, shooting (where legal), and toxic gassing if the tunnels are not close to the barn or home.


It's far less troublesome to prevent wild animals from taking up residence in your barn than it is to get rid of them once they've moved in. Good sanitation and maintenance are the keys. Keep the barn in good repair (especially by plugging up holes) and keep all food and grain swept up and securely contained in metal containers. Then enjoy wildlife where it belongs--in the wild.

About the Author

Marcia King

Marcia King is an award-winning freelance writer based in Ohio who specializes in equine, canine, and feline veterinary topics. She's schooled in hunt seat, dressage, and Western pleasure.

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