Mice for the most part are a minor irritation. More often than not they find their way into your house to chew on some hidden feast at night.

Rats on the other hand are a whole different ball game. They are bigger, stronger and hungrier. Native to Ireland is the brown rat and depending on its habitat it can appear brown or grey. Size, like colouration, varies depending on a number of factors. But a male can weigh as much as half a kilogramme. A female is typically smaller and lighter.

Rats can be a serious pest and and present a significant health risk to humans. Rats potentially harbour a number of disease-carrying organisms such as mites and fleas plus they spread Weil’s disease in their urine.

From a pest perspective, rats will easily eat their way through timber feed-house doors or bulk bags to get to animal feed or seed grain. Worse than that, the rat’s national pastime seems to be chewing on anything that presents a challenge.

Ducting for grain driers or heating/cooling systems, water pipes and electric cables are all fair game as far as rats are concerned. It is the latter that potentially causes the most damage to farm buildings, domestic dwellings, agricultural machines and farm vehicles.

Best-case scenario is a loss of function such as shed lights or car, tractor or jeep electric functions. Worst case scenario is fire and the loss of a building or vehicle to fire.

A combine harvester never moves for nine or ten months of the year and provides a veritable playground for rats and mice.

No matter how well you clean a combine harvester, there will always be a few grains or heads to provide furry squatters with a protein-rich diet. When they get bored, there are lots of rubber seals and flaps to chew on and exercise their jaw muscles.

The insulating on the different-size wiring provides a technical challenge. Stripping the insulation off sections of wiring while leaving the copper intact hones the rodent’s skills and dexterity.

Occasionally they will lose patience, or have a bad day and chomp straight through the copper wire. But their skills at stripping electrical wiring are excellent and even a little scary when you see a wire as thick as a pencil chewed through.

It’s not just static, seasonal machines that are affected by rodent damage. The close proximity of the farm’s car or jeep often makes them very attractive too for these mini munchers.


In the cold of winter, the warm engine and gearbox provide a comfortable sleeping environment. Engine covers top and bottom on modern vehicles make it even snugger. Some wiring, wiring armour, windscreen washer piping or diesel fuel piping provides something to nibble on if they can’t sleep.

Even scarier is that one occasionally finds its way into the vehicle’s interior, either through an open door or boring its way through a weak spot in the vehicle’s construction. Food deposits, particularly from a young family, provide the nibbles.

Adding to the freak-out-factor is if the lodger turns out to be a rodent of the larger type.

What can you do to protect yourself, farm and family? Quite a lot really – being proactive in controlling the rodent population is very important. Traditional predators of rats and mice are cats, owls and even foxes.

Cats, particularly female cats, are good at controlling rodent populations but present their own health risks. Trapping is an option, particularly for mice, but is less effective (and less pleasant) where rats are overpopulated.

In reality, consistent and planned baiting is the most effective method of controlling the rodent population. Baiting has to be consistent and regular to effectively control the problem population.

Once eradicated, it is often the case that another population will move into the vacant position. So, again consistent and regular baiting is required to provide consistent rodent control.

If the infestation is particularly, bad then consider a pest control agency. A pest control agency can provide different levels of action to suit different budgets and infestation levels.

Extreme care needs to be taken when laying bait so that children do not have access to it. Similarly, precautions are necessary if there are dogs resident on the farm or poultry in the case of bait-laced grain.

In relation to the family car it is important to do the basics. It is normal for kids to abandon the car as if it is on fire on returning home, then argue about who was last out and who should close the doors.

A door is left open on occasion. Like any family car, food remnants and a cosy environment are pretty attractive to the rodent population. And there are lots of places to hide within a vehicle, comfortably sharing the same space as human occupants completely unnoticed. So, educate all to close doors on exiting the vehicle, and explain the reasons why.

It is impossible to make a farm completely rodent-proof but there is much that can be done to keep them out of or away from essential feedstuffs and farm systems/electrics.

Proper meal storage facilities help prevent rodents from contaminating animal feed. Metal trunking and armoured cabling protects electric cables from rodents’ sharp teeth.

Rodents will live among bales in a shed but also in cavities in walls and under floors. Patch damaged walls and floors where possible to close the door on possible occupation. In general, good housekeeping around the farm also reduces the number of possible dwelling places for rodents.