RATS have been “our best worst friends for the past 10,000 years” – but as the pest problem continues to hit headlines, experts are cautioning that the solutions are complex.
In Scotland, more than 24,000 rat infestations were recorded in residential homes last year, with Glasgow city accounting for about 40% of these cases.
The figures released by Direct Line Home Insurance through a Freedom of Information request to councils showed that reported cases in North Lanarkshire Council increased by 28% when compared with 2020 while those in Edinburgh City more than doubled.
Other countries are in the midst of taking more drastic solutions. New Zealand has vowed to exterminate its rats by 2050.
However, Alex Wade, the founder of Wade Environmental, which consults on public health and pest management, warns that their situation is very different.
“New Zealand has a very specific ecosystem and rats are not adapted to that in the same way they are adapted to our ecosystem,” he explains.
“With the impact they have had on our flora and fauna, we do not have the same urgency that they do.”
Rats, rabbits, possums and stoats are non-native to New Zealand and kill 25 million native birds each year while preying on lizards and other animal species.
In Scotland, wiping them out completely could harm the ecosystem, the experts warn.
“The first thing to keep in mind is that rat is not synonymous with the word pest,” Wade continues.
“A pest is like a weed, a plant that is in the wrong place. A beautiful ivy can become undesirable if it starts to damage your brickwork or dislodge your gutters. When rats get into a property and begin to cause distress to the owners, then they become annoying.”
When the animals aren’t in the home, they can clean up the environment by eating rubbish others throw away.
They move seeds around, sometimes storing them underground and not returning to them, which in turn grow into vegetation.
Rats are also prey to some animals when they are out and about, and eradicating them will only bring hunger to their predators.
There are plenty of negatives, of course. The rodents can be very destructive with their chewing, for example.
“They chew to feed but also to keep their teeth sharp,” explains John Horsley, a technician at the British Pest Control Association.
“You’ll find them chewing things like pipework in sinks and dishwashers. They can chew that pipe that removes all the waste from dishwashers.”
Rats also spread diseases because they excrete around 40 droppings a day – though that is around half of the figure for mice. New Zealand has come up with a Predator Free 2050 strategy, with the Department of Conservation (DOC) pushing to have all non-native predators removed.
Animals like rats fall into this category because they take eggs, young animals and young mammals from their nest where possible.
The goal of public health pest management is not to eradicate rats but to keep humans and their companion animals safe from the harm that they can bring. Wade said that the government of New Zealand and the DOC had set aside a large sum of money to encourage manufacturers, distributors and innovators to come up with safe, effective, and legal forms of rodent control.
“We need support from government bodies to help us find solutions. It is more productive to be of assistance rather than assuming that one might be found,” he says.
Innovators have come up with solutions that are rodent specific and will not affect other wildlife while also lowering their impact on the environment.
To help them achieve the predator-free goal, New Zealand carries out autopsies on dead rats to determine the cause of death and monitor the effectiveness of the toxins used on them.
There is a programme in place run by the Rodenticide Resistance Action Committee (RRAC), a European-based initiative, and Campaign for Responsible Rodenticide Use (CRRU) which is UK based, where the tails of various rats around the UK and Europe are sent to establish their resistance profile.
“So, pest managers are better able to pick the right chemicals and the right intervention methods to control populations of rodents in their area,” Wade added.
This means taking care if you want to rid yourself of rats when you find them in your house – you might be using the wrong rodenticide for the wrong rat.
Horsley explained that the two main resistance problems in Scotland are genetic and behavioural. If you have got an area where there are behavioural-resistant rodents, they could avoid traps or some types of traps.
Genetic resistance is passed down from parents to their offspring and this is their ability to survive a potentially lethal dose of anticoagulants.
He adds: “So, if you don’t know what you’re doing and you use a particular anticoagulant or rodenticide, you’d be providing them with a food source because even though the rodenticide is designed to treat rodents, if the rodent is resistant to it, then it becomes a food source to them.”
Research continues on how to control rat infestation because, as Wade puts it, “pest management is an ever-evolving industry. We are dealing with animals which are highly adaptable. They have been our best worst friends for the past 10,000 years”.
It is even better to not have them come into your property in the first place, the experts advise.
It is always easy to look around your property to see if there are any gaps or holes and fill them in. It might not stop all pests from entering your property because they may find other ways. But if you’ve sealed all holes, and they still find their way in, it makes it easy to identify where the actual problem is coming from.
This should be done only before they get in because sealing the holes after that will only force them to other areas of the house.
Stressing the role everyone must play, Wade concludes: “In Glasgow, there were big issues with bins where waste was left to pile up and that led to a huge increase in the number of, not necessarily rodents, but visible rodents on the streets.
“You can see how much of an impact things like waste management have on the population of rodents.
“So, we have a social duty of care to reduce [the chance of] these animals becoming pests in the first place.”
