Rodent control in household and summer cottage environments

Mice and rats are the most common rodents to be controlled in flats, summer cottages and outhouses. They cause harm by contaminating premises and foodstuffs with their droppings and by damaging buildings and objects. 

Guide to prevent rodent damage and control rodents

To prevent rodent damage, it is important to keep the premises clean and tidy, to remove rodent food sources and to prevent the entry of rodents into buildings. Observe at least the following:

  • Seal any holes rodents could use to enter the building. You can also use a sufficiently close-knit mesh to prevent entry. A mouse can enter the building through a hole through which you can stick a finger!
  • Mice are good climbers. Make sure that they cannot enter the upper parts of the building using, for example, electric wires.
  • Keep the surroundings of buildings tidy. Rodents hide, for example, in piles of boards or leaves.
  • Put waste in containers with a lid.
  • Store any foodstuffs and pet foods in a manner that rodents cannot reach them.
  • Seeds dropped from bird feeders attract rodents. Keep the feeding areas tidy and preferably use feeders that rodents cannot get into.
  • If preventive measures fail, you may control rodents with lethal traps. Place the trap in such a manner that it does not cause harm to other animals.
  • Tukes recommends using lethal traps as a priority. Live traps may only be used by persons capable of killing the animal as quickly and painlessly as possible. Live traps must be checked daily. Tukes does not recommend the release of rodents, at least in urban areas.
  • As a last resort, it is possible to use rodenticides for rodent control.


What are rodenticides?

Rodenticides are used for controlling mice and rats. Most rodenticides act as anticoagulants by affecting the vitamin K cycle. As a result of blood-clotting problems rodents die of internal bleeding about one week after ingesting poison. Alphachloralose is a fast poison that kills mice within a couple of hour of consumption.

Rodenticides are also poisonous to humans – children in particular – as well as other mammals and birds. The poisoning primarily occurs through the mouth or skin. Be careful when handling poisons, use protective gloves and place poisonous substances out of the reach of children and other animals.

Other animals may be exposed to poisons when eating rodenticide baits or rodents that have eaten rodenticide. In Finland, residues of rodenticides have been generally found in eagle owls, tawny owls, genus Corvus birds, foxes, raccoon dogs and genus Mustela animals. Most rodenticides are very long-lasting compounds that leave the rodent’s body slowly.

If you are exposed to redenticides, contact Poison Information Centre

If rodenticides have been used as instructed, there is no risk of poisoning. Accidentally ingested rodenticide may cause a poisoning. Rodenticides contain bittering agents for bad taste to prevent children from eating the bait. Colouring agents have been added to rodenticides to make it easier to detect potential poisoning in children or pets. If you even suspect a poisoning, contact the Poison Information Centre (0800 147 111) immediately or seek medical assistance and show the rodenticide package.

If a pet has eaten rodenticides or a poisoned rodent, contact a vetenarian.

How are rodenticides used?

Rodenticides are used as a last resort to destroy rodents. Pay attention to at least the following matters:

  • Consumers can buy rodenticides intended for controlling mice only.
  • Rodenticides are packaged in pre filled bait boxes and they can only be used indoors.
  • No rodenticides for controlling rats have been authorised for consumer use. Rats must be destroyed by trapping. If this does not work, please contact pest control operators.
  • Read the instructions for use carefully and follow them.
  • Place the bait boxes in a manner that children and pets cannot come into contact with them.
  • Remove the baits after the control treatment period and dispose of them as hazardous waste. Poisons must not be used on a continuous basis. If you fail to get rid of mice, please contact a pest control operator.
  • Find and collect any dead rodents and the baits they have carried away during the control treatment. Place the dead rodents in a waste container with a lid so that other animals will not reach them.
  • Use protective gloves when handling dead rodents, poison baits or bait boxes.