They’re small, move fast, spoil feed and spread disease. Rats, mice and other small rodents are barn visitors that you can do without. Do you have them, and if so, how do you get rid of them?
Looking for Signs
Are there rats, mice, voles or other vermin living in your barn? Don’t assume that your barn doesn’t harbor any of these pests just because you never see them scurrying across your floors. Most of these animals are nocturnal and don’t like to be seen, but you can look for other clues. They leave droppings where they eat. Again, you may think that you don’t have a problem because you have never seen droppings around your grain bins. However, rodents do not necessarily eat where they find food. They prefer to carry their food to a nearby corner or some hidden spot, plus, they may not always feed at the same spot. So you might have to do some searching.
Other signs that there are rodents in your barn? Look for wood or other material that has been chewed. Also, if these pests are traveling along the edges of a wall, you may see what are known as rub marks. These marks are caused from the oils and associated dirt in the animals’ coat. It will look as though you had a bit of Crisco on your hand and rubbed it on the wood. Typically, rub marks signify a fair amount of rodent activity.
Eliminate the Incentive
The first step in getting rid of rodents (and indeed, in keeping them out in the first place) is to make your barn as unattractive as possible to these vermin. “There are three elements for any rodent to live: food, water and harborage,” explains Dr. Harold Harlan of the National Pest Management Association in Dunn Loring, Va. “Sanitation is very important in this process. Don’t leave uneaten food out in the stall, and don’t just put the excess food in a plastic bag. It needs to go in a waste bin that can be sealed. All food needs to be in heavy metal containers, not wood or plastic. And that metal needs to be at least 19-gauge sheet metal (the lower the number, the thicker). It is not unusual for Norway rats (the most common variety) to chew through metal.
“Controlling water intake is harder. House mice don’t require water; they get enough in their diet. Norway rats do need liquid water almost daily, but they’ll usually find it at a dripping spigot or any standing water. So food is the primary thing to control.
“Another thing,” continues Harlan, “is to eliminate places where they can hide. Norway rats may travel over 100 feet to a trash receptacle if there is a really good habitat spot, so cleaning up trash and eliminating places where they can hide and nest is a must. Try to limit their access to nesting material. Mice like fluffy stuff like cloth. They can, however, nest right in bales of hay. Therefore, it can be pretty hard,” admits Harlan, “to completely rodent-proof a barn.”
Trap ’em, Zap ’em
What are the best ways to get rid of rodents once they take up residence in your barn? There are quite a few mechanical controls that can reduce the population of rodents rather quickly. They include:
SNAP TRAPS—These can be quite effective if placed in proper locations and baited correctly. House mice are quite curious and might be enticed into a trap with something as simple as tin foil, while Norway rats tend to be very shy of new things in their environment and so may take a few days to approach the trap. Don’t use cheese; instead try peanut butter. It smells like a grain and is formulated in an oily base which rats like.
LIVE TRAPS—The ones made for mice work quite well; however, the larger ones needed for rats are not quite as effective. Again, because rats are shy, it will take a little while before the rats will approach, and if two or more rats are trapped, they are likely to kill each other. Rats may return after more than a 1/2-mile distance removal, so you will have to release them far from home.
GLUE BOARDS—You can either put bait in the center of the board or simply place the boards in established runways. Rodents usually die within a couple of hours as they go into a state of shock soon after entrapment.
ELECTRONIC REPELLERS—These are meant to make pests leave the area. Repeated, scientific studies have shown that these devices will get the rodent’s attention for a few days but then the animals just ignore them.
ELECTRONIC TUNNELS—These are metal containers that the rodent walks into and then gets electrocuted. They can be effective, “but,” cautions Harlan, “I have concerns about them. If you aren’t careful using them, or if the device itself isn’t properly constructed, there is a risk of shocking the human. Also, even though these devices are mostly high voltage, low amperage, there is enough amperage there to cause a spark if there is a problem.”
CHEMICAL CONTROLS—When all else fails, you may have to resort to chemical methods of control. Harlan, while not against using poisons, cautions that they should only be used as a last resort, and used with great prudence. “Read the label very carefully. I would also suggest that any baiting be done in a tamper-resistant bait station that you may have to buy separately. If you are devising your own bait station, then you have to be very careful that other animals and children can’t get to it. I’d also advise against any heavy metal poisons which can build up in a rodent’s body and may become a source of secondary poisoning.” Stay away from products that come as treated, loose grain or in a loose, pellet-like form that can easily fall or be shaken out of a bait station. Also, some rats will kick this type of bait out of the bait station or carry it off and leave it somewhere else. A better alternative is to use baits that are sold as blocks. These can be secured on a rod and can’t be moved.
Finally, Harlan advises people not to “mix up chemical treatments yourself. Dealing with toxicants is not a good idea unless you are trained to handle them. There are too many things that can happen, and most of them are bad.”
Rodent control is something that must be practiced at all times. Whether or not you have a problem, keeping a good, clean barn will keep pests away and, instead, create an enticing place for visitors of the human and equine variety.
Cat and Reptile Allies
Many barns employ the age-old practice of keeping a few barn cats to manage the rodent population. Does it work? Surprisingly, for the most part, no. Cats are not able to get into all the small crevices and holes where rats and mice like to hide. And even the most aggressive cats are rarely able to keep up with an exploding rodent infestation.
A better alternative might be the use of snakes. Certain species eat rodents and small mammals and can be quite efficient at reducing pests around the barn. For those that are squeamish, snakes are burrowing and nocturnal so you are unlikely to come upon them suddenly in the barn. Varieties such as the Indigo (also known as the Black Snake) and Racers are excellent choices.
But be sure to check with a local wildlife expert before inviting snakes into the barn as some rodent-eating snakes can be poisonous. —EF