Rodent Control Measures
Rodents like to live where people live and they can thrive on just an ounce of food and water a day. If they come upon a human-inhabited place that offers them food, water and shelter, they will stay.
Rodents are attracted to small spaces because they feel protected in them. If a space is small enough for rodents to access, but not for their predators such as cats and dogs, Rodents will make a home there.
Rodents can make homes in anything that provides shelter including sheds and garages, wood or rock piles, under enclosed patios and stairwells, and in unwanted items such as old water tanks, appliances, building materials and tires.
Some key points for Rodent prevention, Rodent proofing, and eliminating Rodents are found below:
Do not store garbage outside; place it at the curb no earlier than 6 a.m. on your garbage collection day
Remove bird feeders or attach catch basins so bird feed does not fall on the ground
Remove pet food right after feeding and do not leave it outside overnight.
Trim plants near buildings so that 6 to 8 inches above ground is clear. Trim branches of trees or shrubs to prevent access to roofs or balconies.
Do not pile wood on the ground - instead lay it against raised posts.
Remove fallen fruit and nuts from your yard.
Compost properly - do not add fish or meat to backyard compost bin
Do not store old cars or furniture outside.
Repair any plumbing leaks to remove a water source.
Cover pools and whirlpools when not in use.
Lumber, rocks, garbage, building materials, and other unwanted or unused materials should be removed
Do not enclose the base of patios and raised stairwells, not even with lattice
- Make it impossible for Rodents to get into any structure
- Repair all openings with a strong material (cement, metal, etc.) to prevent entry.
- Use screens in drains and tightly seal where utilities enter buildings
- Install a metal kicking plate or heavy weather stripping beneath doors, including garage doors
- If building a patio or shed on a grade, bury sheet metal 30 cm (12 inches below the grade and skirting
- Check for signs of chewing damage, fecal droppings or squeaks, chirps or gnawing sounds coming from within walls and ceilings
- Spring loaded traps: bait three of them in a row. Bait with dried fruit, peanut butter mixed with oats, or cheese. Set the traps at ‘right angles’ (90 degrees) to the walls where the rodents are known to travel, with the bait side of the trap toward the wall.
- Rodent extermination is best done by a professional pest control operator. Look up 'Pest Control Services' in the Yellow Pages or online.
The Norway Rodent, also known as the sewer Rodent, harbour Rodent, wharf Rodent or common Rodent, is the only species occurring in Newfoundland. It is not native to North America, but is believed to have been introduced by early settlers when their Rodent infested ships first visited our eastern shores. The Norway Rodent quickly spread and became a serious pest.
Norway Rodents are large rodents that may weigh in excess of 500 grams. They can reach lengths of 40 cm, and their tails alone may measure 21 cm. The body of the Norway Rodent is covered in shaggy fur that is brown or gray in color. The ears and tail are covered in scales, and the tail is shorter than the head and body. Droppings are capsule-shaped. The life-span of a wild Norway Rodent may extend from nine to 14 months.
The Norway Rodent reaches sexual maturity in two to five months and can breed any month of the year. Litters may number from four to 22. Females can have three to 12 litters per year. Adults generally live up to one year in the wild. Born in a nest about 21 to 23 days after conception, young Rodents are naked and their eyes are closed. Females may mate again within a day or so of littering.
At about three months of age the young are reproductively mature. The females come into 'heat' every four to five days and remain receptive to males for a day or two.
Rodents have an excellent sense of balance and, like a cat, a falling Rodent always lands on its feet. A Norway Rodent can drop as much as 15 meters (50 feet) without being killed or seriously injured.
Norway Rodents are good swimmers. They are able to swim up through floor drains and toilet bowl traps. They may swim as far as 0.8 km (½ mi), dive through water plumbing traps, and travel in sewer lines, even against substantial water currents.
The Norway Rodent can climb quite well when necessary. When Rodent proofing a structure, it would be wise to consider that Rodents can:
Climb both horizontal and vertical wires
Climb the inside of vertical pipes that are 4 to 10 cm (1.5 - 4 inches) in diameter
Climb the outside of vertical pipes that are up to 7.5 cm (3 inches) in diameter
Climb brick or other rough exterior walls which offer footholds
- Burrowing and Gnawing
Burrow vertically 1.25 meters (4 feet).
Gnaw through a wide variety of materials especially if a small hole is present, including; lead pipe, brick, cinder block, aluminum sheeting, plastics and glass.
Gain entrance through any opening that is larger than 1¼ cm (½ inch) square
Rodents are omnivorous and feed on a variety of food sources. If given the choice, they will consume meats, fruits, grains and nuts. Dead animals also serve as a food source for these Rodents, and they are capable of catching small fish and rodents. They require water to drink, and they make their colony as close to a water source as possible. Rodents are a nocturnal animal which means they are most active at night.
Rodents can be very aggressive with other Rodents, especially when they become numerous. Dominant males exclude other males from the burrow which may be occupied by several females. This is one major cause of Rodent migration. Again, migration will occur when all suitable habitat is occupied or if available food is not sufficient to sustain the present population.
Reaction to Strange Objects
Rodents will often avoid strange objects, and other changes in their environment for three or more days. The Rodent will recognize a trap or poison bait only as a new object to be avoided; something which may be hazardous. A change in location of a familiar object may cause avoidance, or a noticeable drop in feeding. In environments where strange objects appear regularly, such as at dumps or in busy warehouses, Rodents may show little evidence of shyness.
There are four steps which are usually required in any Rodent control program:
Remove food sources
Remove potential shelters
The 'bottom line' to long-term rodent control is the fact that rodents must have adequate food and shelter to live and thrive. Thus, whenever there is an abundance of Rodents (or mice), there is usually also an abundance of food and shelter available to the Rodents. The removal or reduction of these factors alone via sanitation practices will have a tremendous impact on reducing rodent populations, even without the use of any rodenticides or traps.
- Remove Food Sources
Around residences, it is important homeowners conduct proper waste management, storage practices and feeding of pets and wildlife.
Garbage should be properly contained and removed regularly.
Bird feeders should be removed or designed to eliminate Rodent access by attaching a catch pan to prevent spillage on the ground.
Pet owners should feed dogs and cats only what they will eat and then remove the food and any spillage.
Store pet, wildlife food and lawn seed in an area not accessible to Rodents or in rodent-proof containers.
- Remove Potential Shelters
Rodents must have shelter and nesting sites in order to survive and multiply. Rodents move undetected along runways which are sheltered by tall grass, shrubs or rubbish. They nest in well protected, undisturbed places; under wood piles, under improperly maintained compost bins, under patios & sheds and in unwanted items such as old furniture, appliances and vehicles.
Grass, weeds and other undesirable vegetation adjacent to buildings and fences should be removed.
If the area around building is landscaped, it should be properly maintained.
Lumber, rocks piles, rubbish, old equipment, construction materials, etc., should all be eliminated if possible.
Items which must be kept should be stored at least 46 cm (18 inches) off the ground and 30 cm (12 inches) away from walls and fences.
- Rodent Proofing
The most successful and permanent form of Rodent control is to 'build them out', that is, make it impossible for Rodents to gain entrance into any area or structure where they are not wanted. All places where 'food' is stored, processed, prepared, or fed to pets or wildlife should be Rodent-proofed. If Rodents can be denied access to hiding places and food they can not survive.
- Drains and conduits:
- Use 12 mm (½ inch) screens with 6 mm (¼ inch) holes in drains. Keep them in good repair, tightly seal all areas where utilities enter buildings.
- Construct concrete floors and foundations of high quality materials.
- In the case of patios and sheds built on grade, use sheet metal buried 30 cm (12 inches) below grade to skirt the structure.
- Always use screens in open doors, windows and crawl space vents.
The spaces beneath doors, especially garage doors, should be checked and reduced using a metal kicking plate or heavy weather stripping.
Norway Rodents can be deterred from climbing vertical pipes by applying a 30 cm (12 inch) band of glossy paint around the pipe or conduit.
- Eliminate Rodents
As the Norway Rodent has such an enormous reproductive capacity, controlling the spread of this species means eradication, followed by year-round inspections to ensure the problem is corrected.
In a community-wide rodent control program, poisoning Rodents is an essential part of the plan. Timing of the poisoning effort is of utmost importance. Rodent poisoning methods are applied most effectively before sanitation and cleaning programs are begun to prevent out migration of Rodents to other areas. Also early in the spring where burrows are easily recognized and prior to initial breeding of mature Rodents.
Forms of eradication:
Ultra sonic devices
Whichever method of eradication is used, it is best conducted by a professional Pest Control Operator. Look for 'Pest Control Services' in the Yellow Pages or online.
Precautions and Legal Implications
All rodenticides are potentially dangerous enough to cause death to animals other than rodents, so be sure to place them where they are inaccessible to children, pets, livestock and wildlife.
Read and follow the rodenticide label instructions.
Dispose of dead Rodents immediately and avoid handling Rodents with bare hands.
When baiting outdoors, put all bait deep into burrows or in covered rodent bait stations. If placed directly into burrows, baits must be contained in their original packets unopened. This will prevent spoilage caused by moisture and insects, as well as making it recognizable as a poison. The burrow should then be covered to prevent access by children or non-target animals.
When baits are placed indoors, use covered bait stations where possible. It is legal to use open bait trays indoors only when they are protected under equipment, furniture or some other fixed structure which limits access to humans or animals.
Note: We strongly advise against baiting indoors as there is always a chance of rodents dying in the walls and creating a foul odour.
Also, no matter what form of eradication method is used, it has to be placed where the Rodent will come into contact with it, ie. adjacent to a wall, behind objects.