Mice: Prevention and Control

By Millie Reynolds, Home Economist

Updated in June 2015 by the Manitoba Association of Home Economists

Preventing mice from taking residence in or around your home requires constant vigilance and attention.

Mice may be portrayed as cute little critters in storybooks but in real life mice they present ongoing problems for the consumer. Not only are they a nuisance, causing damage and destroying items by chewing, but they can also contaminate food items and are carriers of disease.

Warding off Mice

  • Keep premises and yards clean. Dropped fruit and nuts need to be cleaned up.
  • Store pet food and birdseed in lidded containers.
  • Do not leave uneaten dog and cat food in dishes. Remove food the pet has spilled around the dish.
  • Frequently clean the ground under bird feeders.
  • Stack firewood, bricks and other similar items off the ground and away from the house.
  • Store items in the garage off the floor. Sweep and hose the garage floor frequently.
  • Check the foundation of the building. Mice can squeeze through an opening the diameter of a pencil so cracks should be repaired. Plug tiny spaces located where the house rests on the foundation because they can become an entry point for mice.
  • Seal entry points for utility wires and pipes with material such as caulking compound mixed with steel wool.
  • Make sure doors and windows fit tightly.
  • Ensure gutters and water drain away from the house.
  • Leave traps permanently set in obscure places inaccessible to pets and children and check them frequently.

Signs of a Mouse Infestation

  • Droppings – mouse feces are rod shaped, black and pointed at both ends. They are about 2- 6 cm (1/8 inch) long and are scattered around.
  • Chewed holes in birdseed or cereal bags.
  • A small animal scurrying into a dark area or under something.

Eradicating Mice

Mice reproduce rapidly so if you think you have one, you probably have more.

  • Traps
    • Traps are inexpensive and may be purchased at a garden or agriculture centre or any store that handles hardware items.
    • Traps are not as dangerous as poison.
    • The mouse is easily disposed of.
    • No smell remains from the decaying animal.
    • Set trap close to wall, in dark corners and places that mice have left their droppings.
    • Set many traps and place no further than 3 metres (10 feet) apart.
  • Glue board
    • Sticky glue boards are available at most garden, agriculture and hardware centres.
    • The mouse sticks to the board as it walks across.
    • Do not use if children and pets are around.
    • Temperature can affect the success of the glue board.
    • A live animal will have to be dealt with.
  • Rodenticide
    • Available from garden, agriculture and hardware centres.
    • Since this is a poison, follow instructions on container for handling, storing and using
    • READ instructions and follow carefully.
    • Place in several locations inaccessible to children and pets.
  • Sounds
    • Using sound to frighten away mice has not proven to be effective.

Disposal of Dead Mice

  • Wear rubber or plastic gloves when disposing of rodents from traps or disinfecting items associated with mice.
  • Double plastic bag dead rodents and dispose of them in the trash can.
  • Traps are not costly so consider disposing of the trap along with the dead rodent.
  • Thoroughly wash gloves in warm, soapy water after handling dead rodents or traps. Wash hands well.
  • Thoroughly clean and wash areas when mice have been evident.

Deer Mice

Deer mice live outdoors and rarely come into occupied houses. They nest in rural areas: tree stumps, under logs and under piles of debris. Adult deer mice have a white underbelly and have large, hairless ears. They are active at night.

Deer mice may harbour the Hantavirus, which is passed on through their saliva and droppings. Hantavirus rarely infects people, but about half the people infected die. Symptoms include fever, chills, muscle aches, nausea, and stomach aches followed by breathing problems.

Precautions need to be taken when working in areas where deer mice may be present. Wear a tight fitting mask. Do not undertake activities that disturb droppings and saliva that cause them to become air-borne. Hosing down areas before entering may be helpful. If, within a few days, it feels as if flu is coming, seek medical help immediately. Tell the doctor about working in an area that may have had mice present.

Continual care, alertness and action are needed if the home and its environs are to be kept free of a mouse infestation.