If you have rats, most of the work is outside the building, and that is the part nobody expects.
Health Canada’s description of the animal is the reason. The Norway rat, which is the rat that turns up in this part of Ontario, builds elaborate systems of tunnels and burrows at ground level, and prefers damp areas like crawl spaces or building perimeters. It has an address, and the address is outdoors. So pest control for rats is a survey of the ground before it is a trap, a bait station or anything else.
That single fact explains most of what goes wrong with a rat job, including the one people try themselves.
Make sure it is a rat at all
Health Canada puts an adult rat at up to 0.5 kilograms, a pound of animal. That is loud. If you are standing in a bedroom asking yourself whether you really heard anything, the answer is usually that you did not hear a rat.
Attic scratching is the commonest reason somebody says the word rats, and on a Norway rat the attic is the least likely place to find one, because the animal lives at grade. Start with the guide to attic noise identification instead. The droppings table on that page is conclusive, and it costs nothing to look.
This matters commercially as well as diagnostically. A rat program and a mouse program are priced differently and built differently, and a company that quotes before it has identified the animal is quoting a guess.
What a perimeter survey actually walks
The survey is a slow lap of the ground, not a tour of the rooms. What it looks at:
- The strip of soil tight against the foundation, and any ground that stays damp after the rest has dried.
- Under decks, steps and porches, and behind deck skirting where a gap lets something in at the rim joist.
- Behind and under the woodpile, the compost bin, and the shed floor if it sits on grade.
- Around waste storage at a commercial property, which is the one place in our area where rats are more plausible than mice.
- The run itself. Rats reuse a line, so look for a smoothed path through grass, a rub mark along a wall at ankle height, and burrow entrances at the base of a slope or a foundation.
Around here that list has a geography to it. The low ground near the harbour and the waste enclosures behind the commercial strip are the reliable spots. So is a farm property through Clearview with feed stored at grade. On a chalet under the escarpment the ground under a deck stays damp all season and nobody has looked at it since it was built.
None of that is a wall problem, and none of it is solved from inside the house.
Why the trap you set caught nothing
This is the most useful paragraph on this page, and it is not our opinion. Health Canada’s trapping guidance says to allow a warm-up period of 3 to 4 days, baiting the traps but not setting them, so that the animal becomes comfortable taking the bait.
Nobody does this. A trap gets set the evening it comes out of the packet, the rat finds a new object sitting in its established run, and one near miss teaches it that the object is dangerous. That location is now unusable, and so is that style of trap for a while.
The same guidance is specific about quantity. It says to set 1 trap per metre along walls, or 5 to 10 traps per visible hole, and to reset the traps in 2 to 3 weeks to catch maturing animals. A single trap in the middle of a room is not an attempt at control. It is a sample.
If the bait stops disappearing, the traps move. A run that has been disturbed gets abandoned, and the animals shift to the next one rather than leaving.
Bait is not the program
Health Canada states plainly that baits or poisons should not be used as the only method of controlling rats and mice, and that rodent-proofing and sanitation have to run alongside them. That is the regulator saying what the trade says.
Two practical consequences. Where bait sits anywhere a child or a pet can reach, the label requires a tamper-proof bait station rather than a loose block. And commercial class products, including the loose pre-mixed baits, may only be applied by a certified professional, which is a large part of what you are paying for.
Bait on its own with the burrows left open is a standing monthly cost and a population that is replaced from outside as fast as it is removed. That is the same argument as exclusion against spraying, with the burrow in place of the entry point.
The order the work goes in
- Identify the species. Rat and mouse work diverge immediately, and the mouse exterminator in Collingwood page covers where the two jobs part company.
- Map the outside. Burrow entrances, runs, harbourage and the water source, marked and counted before anything is placed.
- Take away the reasons. Harbourage cleared, food secured under Collingwood’s green bin rodent rules, standing water closed off. A rat that has nowhere to live and nothing to drink is a rat with a reason to move.
- Close the structure. Exclusion at grade, in metal rather than foam, so that what is displaced from the burrow does not simply relocate indoors.
- Then trap or station bait, pre-baited and in quantity, following the warm-up period above.
- Verify. A return visit weeks later, because the difference between a finished job and a paused one is only visible after time has passed.
Steps two and three are the ones a cheap quote leaves out, and they are the ones that decide whether step five works.
What to do this week
Raise the woodpile about 30 centimetres, which is Health Canada’s figure, and stand it somewhere other than against the house. Put heavy metal mesh between the soil and the base of the composter, and stop putting fatty or oily food waste, eggs and milk products into it. Deal with the leaking outdoor tap.
Do not clean up dry. If there are droppings to deal with, the method is the same one that applies when a seasonal property is opened in spring, and it is worth knowing before you reach for a broom.
At a commercial food premises there is one more thing: keep dated records of what was found and what was done. An inspection asks for the paperwork as well as the result, and a program without records is hard to defend.
Where a rat is plausible, and where it very much is not, depends on which part of town you are in. The pest control in Collingwood page sets that out street by street. If you already know what you have, start a pest control quote for Collingwood and say which ground stays damp.