Rats and mice need do little more than just be seen to have people in a panic. The usual concern is the spread of disease when, in fact, they are no more likely to pass a disease to a human than any other animal. Indeed you are massively more likely to contract something from a pet animal than any wildlife. Still, a population of rodents left unchecked can grow at an alarming rate and if humane action isn’t taken then someone is bound to take lethal action so it is best to respond quickly if you have rats or mice on your property. Sometimes they might take up residence in a loft and could then cause damage. In this scenario follow the steps outlined on our Squirrels page.
The problem with lethal control
Sadly it is all too easy to walk into a hardware or pet shop and pick up a packet of poison. Not only a hideous death for the intended victim but potentially for pets and other wildlife if used carelessly. Poisoned rodents can easily be picked up by foxes, birds of prey, cats or dogs and, when eaten, potentially make that animal seriously ill.
Rats and mice are naturally cautious animals and are very suspicious of anything new in their environment. They will therefore tend to avoid traps and poisons. They have a highly developed sense of smell and can distinguish between poisoned and untainted food easily. They are quick to learn and once they have seen one of their family killed by a trap or by eating certain foods they will then avoid it. They have also evolved an immunity to commonly used rodenticides and they are becoming increasingly ineffective.
Rats and mice are attracted to your garden or home by two things – food and shelter. If you have the rodents killed but the availability of these things remains constant then the remaining animals will simply breed to replace them. In rodents this happens incredibly quickly and individuals killed by poisoning can be replaced within 3-4 weeks.
Some well intentioned people are taking a more compassionate approach by purchasing humane traps and releasing caught individuals. Whilst we admire their attempts to deal with the problem without killing, this method is as ineffective as killing them. It is also not really humane as rats and mice are territorial. Resident animals may chase away any new arrivals, causing them to flee to an unsafe area, putting them at greater risk of predation and making it harder for them to find food and a safe nesting area.
There is a widespread public belief that live capture and relocation is a humane solution to wildlife conflicts in and around the home and garden. Research to date shows that the technique is not particularly humane. Relocated animals released in an area already containing the species move extensively in an effort to find a new home not already occupied by other individuals. Mortality of such relocated animals is high. In addition, removal of animals may create a vacuum at the problem site which is quickly filled by new animals.
– Maryland Taskforce on Non Lethal Wildlife Management.
The only effective method in reducing rodent numbers is to remove what is attracting them – food and shelter. First of all consider where they are finding food? Do you have pets who are spilling food on your property? Are you feeding birds in your garden? Do you have fruit or vegetables in your garden? Are you storing packets of food where they can be accessed? You need to remove the food source and this will make your property a great deal less attractive. A plentiful food supply will encourage the rodents to breed so if you try simply to remove the rodents they will carry on breeding all the while that food is there for the taking.
Removal of the nesting, shelter and roosting places can significantly reduce many types of vertebrate pest problems.
– Biological control of vertebrate pests, Walter E Howard
Secondly, where are they finding shelter? Are there any burrow holes leading under a shed? Do you have a log pile or compost heap in your garden? Or a coal bunker? Fill any gaps and store compost, logs, coal etc in sturdy sealable containers. Or if they’re actually in your house check your doors, skirting boards, air vents, where pipes go through walls etc for gaps – bear in mind that they can squeeze through extremely small holes – rats through half an inch, mice as little as half a centimetre. Fix brush strips to your doors and fill any gaps with mortar or expanding foam.
By removing food and shelter you will discourage the rodents from breeding and they will disperse and eventually decline in number. It is not as “quick win” as lethal methods perhaps but it is the only long term solution.