The Rodent Problem: Know Your Enemy Before It’s Too Late
It’s the same old story. A story that Steve Von Haden, Midwest business manager for Motomco, hears time and time again as he visits barns throughout the country.
“We don’t have enough people. We broke with disease. This broke down. That broke down. In the end, we didn’t get the bait put out,” Von Haden says.
The devastation rodents cause results in roughly $200 billion in damage to homes, businesses and agriculture every year, the Agricultural Retailers Association (ARA) shared. No one wants to talk about them, but with the EPA’s new proposed mitigation measures for 11 rodenticides and a record year for rodents in the Midwest in 2022, there’s no better time than now to discuss rodent control, ARA said on its website.
“2022 was a great year for rodent populations in the Midwest,” Von Haden says. “More moisture and more things growing mean more rodents.”
Matthew Galloway, Midwest Sales Manager for Ag Rodenticides at Liphatech Inc., says he’s never seen a slow year for rodents.
“Given how these farms are designed and the thousands of pounds of food that are constantly there, once these rodents get in, it's a safe haven and perfect environment for them,” Galloway says. “They’ve got all kinds of real estate to hide in. If farms do not have a preventive rodent control program, rodent populations can overtake a farm in a very short amount of time.”
The problem is rats and mice aren’t just annoying — they can be extremely dangerous. Rodents are the No. 1 vector for disease transmission, so rodent control should be a critical part of your farm’s biosecurity plan, Von Haden says. They transmit over 45 to 50 diseases, 35 of which can be transmitted directly or indirectly to humans and livestock.
“Rodents are reservoirs for diseases like Salmonella, Campylobacter, swine dysentery and Actinobacillus pleuropneumonia,” says Jim Lowe, DVM, director of the College of Veterinary Medicine I-Learning Center at the University of Illinois. “They can maintain infection themselves and carry diseases, which are risks to livestock and food safety, between sites.”
The difference between mice and rats
The most common rodents Midwest farmers battle are the house mouse and the Norway rat. Meanwhile, roof rats are one of the worst rodents to deal with and can be found in the south and on the West Coast.
Rats and mice share some commonalities – they both have poor vision and a great sense of smell and taste. They can squeeze their bodies into a very small opening. Rats can squeeze into an opening about the size of a quarter and mice can squeeze into an opening the size of a nickel.
Mice are skillful climbers. Rats, on the other hand, can climb but prefer to inhabit lower levels of a structure.
Both rats and mice can gnaw on various structures and wires in your home or barn, which can lead to fire hazards. Mice have weaker teeth than rats, which means that any food source that is properly stored in glass or metal can prevent the mice from contaminating it, but that may not be the case with rats. Rats are much stronger than mice and have been known to gnaw through various building materials, including aluminum, wood, glass, sheet metal, and even cinder blocks.
What are the signs of an infestation?
How do you know if you have a rodent infestation? Look for gnaw marks, droppings, odors, runways, rub marks and burrows.
“Seeing rodents is a big sign you have a problem, especially during the day, because rodents don’t like to be out during the day when their enemies are out,” Von Haden says.
Pay attention to the walls of your building and look for dust trails. Rodents often travel the same runway because they have poor vision. They urinate to socialize and communicate with other mice along their runways, he adds. Mice typically travel 15’ to 20’ from their nest while rats travel closer to 100’ away from their nests.
Before you can fight your enemy, you must determine who your enemy is. One sign to distinguish is that rats will often create burrows outside your building, Von Haden says.
Why are rodents difficult to eliminate?
Not only do barns and agricultural buildings have a readily available food source at all times, they also have ample water sources and a great nesting area for rodents to have their litters and feel safe. That’s why any agricultural structure or pig barn can become a problem – all the tools are there for them to thrive.
And rodents thrive. Did you know a typical female rodent will have around 50 babies a year? Once those babies are born, they will breed within a month to six weeks. Six months down the road, that could turn into 600 rodents, Von Haden says.
“Quite simply, they are a nuisance. Their reason to be on this earth is to gnaw and multiply,” Von Haden says.
Consistency is key
Rodents are a year-round problem; however, fall tends to be the time when people see more rodents on the move, he adds. Generally, people don’t think they have rodents unless they see rodents.
“That’s a mistake,” Von Haden says. “Always assume you have rodents, and you should be putting bait out. All agricultural buildings or structures will have rodents of some type. You just don’t want it to get to such high peaks it causes structural damage, diseases and contamination of food sources.”
Being consistent with your rodent control program is key to preventing an infestation of rats or mice on your farm. Von Haden grew up on a farm and understands the challenges farmers face.
“We don’t want to be lackadaisical, but it’s easy to find yourself in that situation,” he says. “Although your goal may be to put out fresh bait and check bait the first Sunday of the month, things happen and get in the way. The tractor breaks down, the pigs get sick, the vet is coming, all these things get in the way. What I’ve learned in my tenure is that the more consistent you are, the less of a problem you’ll have.”
Once a farm gets to a height of infestation, it takes a lot of time producers don’t have. Galloway says that’s a big part of the problem.
“Farms don’t always have the manpower needed to control the rodent populations properly,” Galloway says. “Farms find it difficult to hire people who are able to handle day-to-day responsibilities on site, let alone finding someone to handle rodent control problems.
Understaffing is hands down the biggest obstacle I see on farms that have rodent issues. However, farms that are able to find the right people and take rodent control programs seriously, generally have less issues in the short and long term.”
Win the battle
“Rodent control is not just putting out some bait and calling it good. You have to do it all, and you have to do it all the time,” Lowe explains.
An integrated strategy to remove habitat, control feed sources and provide a continuous supply of fresh bait is critical, he adds.
Read these tips to rodent-proof your barn.
One of the challenges with fighting rodents in your barn is you must take different approaches with rats versus mice, Von Haden says.
“Mice are easier to control because they are so curious. Giving them a different form of bait will make them feel more comfortable,” Von Haden says. “If they don’t eat the bait, try moving it a little. If you move the bait station 10’ to 15’ in another direction, mice are more likely to eat it just because it wasn’t there yesterday.”
Meanwhile, rats are the opposite. They do not like change. Rats may take up to three days to feel comfortable enough to approach bait that wasn’t there before.
“They’ll go up to it and say ‘Hmm, that wasn’t here yesterday, what’s going on?’ For rats, it’s important to come at them from different angles. Rats also need to drink water every day, so having a liquid in the bait station helps,” he says.
Burrow baiting is often a successful way to kill rats, Von Haden adds. Placing a big chunk of bait down a rat burrow will likely make the rat feel uncomfortable as it blocks their entrance/exit. Instead, Von Haden suggests using meal bait. Meal bait disperses down into the burrow easier, making rats feel more comfortable to eat it.
“The key to baiting is if the rodent isn’t eating bait, you have to figure out what problem is – is it not fresh enough? Not in right place? Need to switch up your active from a blood thinner to a non blood-thinner? You may need to give them a little different form of bait,” Von Haden says.
Rodent-proofing your barn or building is important 365 days a year. It only takes a dime-sized hole to result in an infestation that could cost you a great deal of time and money.
“Rodent control is a routine job, 52 weeks a year,” Lowe says. “You can’t get behind.”
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