The Fieldman’s Files – Where do all the rats go?

Above, mouse droppings (left) and rat droppings.

Normand Boulet
CCA, Agricultural Fieldman
M.D. of Smoky River No. 130

If you search the internet for a map showing the global areas infested by rats you will find a map that shows the Arctic, Antarctica and Alberta as being the only areas that are rat free.

The Arctic and Antarctica don’t offer rats a place they’d want to live; only Alberta has to work at staying rat free.

The reason Alberta can brag to the world that our produce contains no Rat feces or urine is that in 1950, Alberta Agriculture decided to stop Rats from moving further west from Saskatchewan.

It was a pivotal point in Alberta’s history. A Rat Control Zone (RCZ) was established from the Montana border to about Cold Lake 18 miles (three Townships) wide where Pest Control Officers (PCO) still inspect, kill rats and remove habitat throughout the year.

Being vigilant is obviously still required as the Rats continue to try and infest our province. The RCZ is only required on the lower half of our eastern border as the inhospitable and sparsely populated border with Montana, the forested area north of Cold Lake and the Rocky Mountains to the West mean the Rats can only come in on foot through the RCZ.

The Norway Rats ability to survive is bound to humans; they need our shelters to hide from predators and access to food.

Shelters might include bale stacks, old houses or granaries.

Unaided rats will not travel more than a few miles so the increasing distance between farmsteads actually reduces their ability to relocate on their own.

However! The reason we need to all be on the lookout, even way up in the Northern interior of the province, is that Rats can also move in via our ever more mobile society. Industrial, oilfield and agricultural equipment, hay, rail cars and vehicles could all be harbouring a rat.

We all need to be on the lookout and if a Rat is seen, it needs to be destroyed immediately.

A bred female and her offspring, safe from predation could conceivably produce 15,000 rats in one year.

Rats are estimated to destroy up to 1/5 of all the world’s crops each year.

They spread disease and parasites and are still spreading the infamous Black Plague (there are known deaths in the US every year).

The fact that Alberta is rat free still makes the news, and it isn’t that rats are not occasionally found; they managed to infest a landfill at Medicine Hat a number of years ago, one managed to fly into Fort MacMurray on a passenger plane, people bring them in as pets and a travel trailer had to be fumigated in the County of Grande Prairie several years ago because it came from B.C. with rats in it.

However, no known breeding populations of rats are established in Alberta.

Rats are a successful invasive species:

The average rat can wriggle through a hole the size of a quarter, scale a brick wall, tread water for several days, gnaw through lead pipes and cinder blocks, survive a five-story fall, survive being flushed down a toilet—and even enter a building through the same route. (Brian Handwerk for National Geographic News March 31, 2003, “Canada Province Rat Free for 50 Years.”)

While doing research for this article I came across a story of South Georgia Island, near Antarctica, which through tremendous effort has been cleared of rats.

At a cost of $13 million and taking nearly a decade, more than 300 metric tons of poison bait was dropped on the island by helicopter to eradicate the rats, which were likely introduced by whalers in the late 1700’s.

Ground nesting sea birds are now free to repopulate the island. Rats are not getting back to this island without help from man so the eradication efforts should hold.

An island, about one-third the size of the M.D. surrounded by ocean can be cleared of rats, what would it take to clear Alberta if Rats were allowed to establish?

The Province of Saskatchewan, Ireland and New Zealand are all working towards rat eradication, so perhaps the rat free status map will look significantly different in a few years.

The reason I wanted to get this article in at this time of year is that Rats are pretty much bound to humanity, as the weather turns colder any Rats that may be present will be searching out food and a place to live, keep an eye out around the granaries, old sheds and bales.

The most likely signs you might see are gnawing as the rats create entrance and exit holes or rat feces which are blunt at both ends and about half to three-quarters of an inch in length (see the image, compared to mouse droppings on the left):

Rats scamper and jump when they move, as opposed to the more stocky Muskrat, which ambles along.

Rats also tend to stay hidden during the day, you will most likely only see one if it was uncovered suddenly.

If you think you’ve seen a rat or rat sign, contact me, it is worth investigating to ensure we never let them get established in Alberta.

It is illegal to harbour any Rattus species in Alberta without a permit. That includes white rats which are sometimes kept as pets.

Only research institutes such as universities and hospitals can keep them in approved quarters.

All Rattus species are classed as pests under the Agricultural Pests Act of Alberta, and as such all landowners or occupants in Alberta are bound by the Act to take active measures to destroy them, and to destroy their habitat.

Part of my duty as an Inspector under the Agricultural Pests Act is to educate and ensure our Province stays Rat free, so if you believe you have seen a Rat, other than a Wood (Pack) Rat or Muskrat, call me – I will investigate and can set traps, poison or call in the troops if that’s what is needed.

The current program costs about $500,000 per year whereas it is estimated it would cost about $43 million each year to have rats in Alberta.

Keeping Alberta rat free is an important goal made possible with a very cost-effective program.

If you have any questions, contact me at (780) 837-0043 or by email at


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