- House mice are small rodents (2-3 inches), greyish-brown with an almost naked tail.
- They prefer to live inside buildings. Chances are the only signs you will ever see of a mouse's activities are slightly gnawed foods and droppings (rod-shaped, about 1/4 to 1/3 inches long).
- Their nests usually consist of loose assemblies of paper, cloth, twine and other material.
- Mice are omnivores, eating a wide variety of foods: seeds, grains, and nuts. They only require 1/10 ounce of food each day and, if their food is moist, can go without fresh water indefinitely.
- They breed year-round and can raise as many as 8 litters annually. Females become sexually mature at 1½ to 2 months of age. Obviously, mice have a tremendous reproductive capacity. This is offset by their short lifespan: they generally live about one year.
- They can carry several diseases transmissible to humans such as salmonellosis.
- There are several species of rats, one of which is of special concern to Canadians: the Norway rat.
- Brought over from Europe in 1775, the Norway rat's distribution is now continent-wide.
- They are incredibly hardy, gaining access to any opening larger than a quarter. They are capable of jumping up to 3 feet vertically and 4 feet horizontally. They are excellent swimmers.
- They average 10-16 ounces, having shorter tails than their heads and bodies combined.
- Rats are omnivorous. They will eat almost anything: grains, insects, meat refuse, bird eggs and even mice. Adults require about 1 ounce of food per day and need access to fresh water. They are mainly nocturnal.
- They are thigmotaxic: they feel secure when pressed against something and will move around the perimeter of a room, pressed to a wall, whenever possible.
- They breed year-round, although peak breeding periods correspond with spring and fall. Sexual maturity is reached at about 2-3 months of age. The litter size averages 8-12 young. A female can wean up to 20 young per year.
- Rats usually live in ground burrows with a few tunnels. They usually have several entrances. They can also build loose spherical nests of shredded material in trees and vines well above the ground.
- Inside, rats tend to nest inside walls, under stacked lumber and anywhere human refuse will tend to build up.
- Rats, aside from mosquitoes, are the most important carriers and transmitters of diseases to humans.
- Moles are largely beneficial to gardens because they eat insects and slugs. One mole will eat its own weight in insects every day: cutworms, wireworms, sow bugs, grubs, centipedes, and millipedes. They tend to like earthworms too (which is not great because worms are quite beneficial for gardens).
- They can sometimes harm plants by removing the earth around the root structure, and their extensive tunnelling may mar the look of a well-manicured lawn.
- Moles are small, greyish-brown insectivores. THEY ARE NOT RODENTS! They usually measure about 12-20 cm in length. They have small eyes and broad front paws for digging.
- Being insectivores, they do not eat plants. They generally earn the bad reputation of being plant-killers from field mice that use their tunnels to gain access to plant roots (to eat them).
- They are solitary animals that do not hibernate and that prefer soft soil. Their tunnels are usually just under the surface of the lawn, creating ridges running along the property. The most telltale sign of mole activity is a raised pile of earth near the entrance of the burrow. Moles are very territorial creatures.
- Moles breed in late winter or early spring.
- In spring, the female usually gives birth to a litter of 3-7 young. These become adults in 4-8 weeks.
- Sometimes known as field mice (not really accurate).
- They resemble house mice but are distinguished by a shorter tail and a rounded muzzle and head. They also have smaller ears. Being rodents, they have a pair of large chisel-like incisors that grow continuously.
- They have dark brown coats with greyish bellies. (The house mouse is uniformly grey).
- They forage for green plants and seeds during the day or night, but prefer the daytime.
- They do not hibernate. They use the insulating properties of snow to remain active in the winter by travelling under the snow.
- Voles will tend to move into old mole tunnels to gain access to plant roots. They can also gnaw the ground level bark of fruit trees.
- Symptoms of vole infestation: bark completely removed from the base of the tree, 1-2 inch wide surface runways through matted grass leading to shallow underground burrows, small piles of brownish feces.
- Females have a large reproductive capacity. They are able to reproduce at 3 weeks of age.
IS THERE A PROBLEM? HOMEOWNER SHOULD ACCEPT NORMAL, UNOBTRUSIVE BEHAVIOR
Refer to SELF-HELP if:
- Problem is repetitive.
- There are any established activity patterns causing problems.
Refer to PROFESSIONAL ASSISTANCE if:
The mice, rats, moles or voles are posing a health risk.
In the case of moles, the best solution is tolerance since moles are largely beneficial and quite difficult to control. If molehills are a problem, simply flatten them down prior to mowing.
Removal of Attractants
- Make sure all dry foods are cleanly stored in canisters.
- Clean up any spilled seeds, breadcrumbs or grains.
- Reduce the availability of shelter (ground cover), water and food.
Habitat Modification & Exclusion
- Mice only need an opening the size of a dime to gain entrance, so any screens used to close off entryways must be roughly ¾-inch x ¾-inch in size.
- It is quite difficult to exclude mice, but this method is the best and only way to permanently deal with a mouse infestation.
- Inspect the area very carefully: spread talcum powder along the edge of the wall. This will let you see where the mice are concentrating their activities.
- There are many different products that can be used: small wire mesh, quick-dry cement, window-screening can be stuffed into a space and then solidified with plaster or caulking, and expanding-foam insulation.
- Outside cover can be eliminated by cutting the grass short and by removing weeds (at least 18 inches away from the foundation).
- Openings (about 1 inch wide) must be closed off with ¼ inch hardware cloth.
- Heating vents are sometimes overlooked when looking for entry sites.
- Mow grass and clear debris close to buildings to reveal burrows.
- To prevent burrowing along foundations, an L-shaped footer can be buried about 12 inches and extend about 12 inches away from the foundation. This footer can be made of hardware cloth or concrete.
- If the affected area is small enough, fence it using an 18-inch metal sheet. It should extend at least 6 inches underground to prevent the rat from burrowing under.
- Create barriers around plants to protect the garden. Bury hardware cloth (¼ inch mesh) in an L-shaped footer. Moles, after encountering a barrier, will get frustrated and give up quite easily.
- Packing the soil in your garden can also make it more difficult for the moles to burrow since they prefer loose soil. In addition, reducing the soil's moisture can also deter moles from burrowing, though both these methods may not be great for your garden.
- Gravel or cinder barriers around gardens are generally effective. The barrier should be 20 cm deep and a foot or more wide.
- Chicken wire or hardware cloth is also useful around the base of trees.
- There are some ultrasonic devices on the market, but none have been scientifically tested for effectiveness.
- Having family pets in the yard can sometimes deter most rodents.
- For more tips go to Mole Controls
- For moles, planting spurge (a perennial) has had some repellent effect. Castor bean is also a repellent, but this plant is highly poisonous to humans so it is not suggested!
- Baits do not work against moles because they are insectivores and will therefore rarely take the bait.
- Vibrations tend to disturb moles, so a toy windmill can be put up near the entrance to the burrow. When it turns, it will create enough disturbances in the air to annoy the mole. An empty soda bottle can also be placed in the mouth of the tunnel. The wind will make a blowing vibration that irritates moles.
- Spray a solution of 1 tbsp. castor oil and 1 tbsp. liquid detergent (Ivory) per gallon of warm water on soil and plants.
- Scatter dog hair about.
- Place elderberry cuttings in the tunnels.
- Sprinkle chilli powder and powdered garlic or ground red pepper or tobacco dust into the tunnels on a weekly basis.
- Place rolled-up pieces of "Juicy Fruit" gum in mole tunnels. Make sure you unwrap the gum with gloves on to mask your scent. Moles love the taste and will readily eat it. Unfortunately for the mole, the gum will clog its innards, causing it to die.
Denatonium benzoate, when sprayed on surfaces to be protected, will deter voles from chewing. It should not be used on food or edible plants.
- The most effective way to control moles is to trap them. There are several lethal traps on the market. Most operate by beheading the animal. The best time to trap them is in spring or fall.
- There are a number of commercial live-traps on the market. Normal mousetraps (the lethal kind) also work on voles.
- However, for mice or voles, the homeowner can make their own trap by using a wastepaper basket: Place the basket (metal or plastic preferable) in a high-traffic area (mice, not people). Bait the trap with bread, sunflower seeds or peanut butter (voles like bacon). Place a ladder of books or bricks leading up to the basket. Make sure that they support the basket, as it should be tilted up against them. The mouse will use the books to climb up and then slide down the tilted basket. It will not be able to climb back out. Check the trap early in the morning. Once set free outside, clean the basket with a dilute (1:30) solution of bleach.
- It is important to note that trapping is only useful if there are a small number of mice.
This is suggested when all other measures have been taken and it is determined that the mouse, rat, vole or mole may need to be removed from the property.
Self-help tactics should be attempted first in all cases involving property damage. If these remedies are not sufficient, removal of the animal may be the only option available.
- Humane Wildlife Control (514-395-4555)
- Exterminators: For a fee, they will remove animals from the property.