Brown rats are causing havoc this summer, say pest controllers – because the roving rodents have developed an aversion to leaving people’s homes.
Natalie Bungay, a technical officer for the British Pest Control Association (BPCA), says pest controllers usually report that callouts for brown rats go down in the summer, because they’re no longer living in buildings.
But this year that’s not the case. “It seems to be that rats are causing a lot of problems to home owners,” she says.
A rat’s typical seasonal calendar sees them seeking shelter indoors in autumn and winter – but in the spring and summer months, when the weather warms up and food is plentiful, they tend to gravitate outdoors.
David Cross, head of Rentokil’s technical training academy, cites two possible explanations for why they’re staying indoors: sufficient, undisturbed harbourage and better access to food and water. “The water is key here as they need to drink on a daily basis.” The average rat needs roughly 60ml per day, he says.
The likelihood is that rats aren’t staying indoors all the time as they’ll need to go out for a drink. “There isn’t that much standing water inside a building, certainly not inside a domestic house,” says Cross. “I would expect that any rat infestation would move in and out of the building, but they tend to be coming back into the building to harbour rather than living outside.”
Rats pose two main issues for humans. The first is that despite being regular groomers, they’re associated with disease, especially when they’ve been hanging around drains.
“If they’re feeding on stuff in the drain then all of that bacteria will then pass through their gut as well, which means their droppings will be laced with bacteria,” says Cross. “Salmonella is quite a common one to find in rat droppings.” And when they come into the kitchen and start foraging for food, they will be dropping that bacteria onto surfaces, he adds.
Another issue is that rats have large teeth which grow continuously and, as a result, they need something to wear their teeth down. “They’ll gnaw against virtually any hard surface – wood, breeze block, anything at all,” says Cross.
“Heavy infestations can actually start to structurally weaken the building,” he adds. “But probably more important than that is if they’re in your attic and quite a lot of electrical cabling runs through the attic – in worst case scenarios they could cause a fire.” The insurance sector estimates that rodent damage to wiring is responsible for 25% of all electrical fires in buildings.
Property owners have a legal obligation under the Prevention of Damage by Pests Act 1949 to keep premises rat and mouse-free. “If you are knowingly harbouring an infestation of rats or mice in your property and you’re not doing anything about it, you could actually be prosecuted,” Cross says.
How To Get Rid Of Rats
How you deal with an infestation depends on how many rats there actually are. The first thing to do is figure out the root cause of the problem and try and do something about that – repair any damage to the outside of the building, fill any holes, fix any drains which might be breached. The aim here is to stop them from coming in – rats only need a gap of 15mm to gain entry – and preventing access to food, water and harbourage. “If they’ve got access to a wall cavity you need to prevent that access,” says Cross.
He lists some simple housekeeping rules that can help to deter rats, things like cleaning up after yourself; making sure dustbin lids are shut; not leaving food lying around; properly storing food in containers and ensuring you don’t leave any puddles or vessels filled with water around for them to drink from.
“Once you’ve got the rats, you need to destroy them,” he says, recommending individual traps for small rodent infestations and rodenticides for large infestations – though the latter can be problematic, especially if you have pets.
Cross advises using base stations for rodenticides so dogs and cats can’t gain access to it. If you’re unsure, call a pest control company accredited by the BPCA, as they have access to a number of rodenticides which aren’t available to the public. It’s crucial that you dispose of any dead rodents immediately.