Moving up the ‘rattiest city’ rankings a dubious honour for Oshawa, Ontario

By Glenn Hendry

Published December 10, 2025 at 8:54 am

Mild winters, construction disruptions and abundant urban food sources have led to an increase in the rat population in many Canadian cities, with Oshawa earning a spot as one of the country’s top 25 ‘rattiest’ cities.

Oshawa just made the cut in 25th spot in the annual list from pest control providers Orkin, which compiles the rankings based on rodent treatments the company performed from August of last year to the end of July 2025.

Oshawa was ranked tenth among Ontario communities, up from 12th last year. No Durham Region town made the top 25 national list last year. Whitby moved up from 25th in Ontario last year to 20th spot in 2025, with Pickering placing 21st.

Ajax was 23rd in 2024 but slipped off the list this year.

Toronto was declared the rattiest city in Canada, according to Orkin, followed by B.C. communities Victoria, Vancouver, Burnaby and Richmond, with Mississauga, Kelowna, B.C., Ottawa, Scarborough and Moncton, N.B. rounding out the top ten.

A recent study found a 15 per cent increase in rat activity nationwide, specifically within a three-year window between 2022 and 2025, and Orkin said in the news release that more regions across Canada are seeing increases in rodent population and urges home owners and businesses “to take precautions to help keep rodents out.”

Here are some tips from Orkin that can help you keep rats and other pests away from your property.

• Trim your trees: Landscaping can be a big-rodent attractant. Keep shrubbery cut back at least one meter from the exterior walls of your home to eliminate any hiding spots for rodents and to avoid giving them a “jumping off” point.
• Cut off the water: Eliminate any moisture sources, necessary for pests’ survival, such as clogged gutters or water gathering in trash or recycling bins.
  Inspect both inside and outside your property for rodent droppings, burrows and rub marks along baseboards and walls. The more quickly rodents are detected, the better.
• Close the gap: Look for possible entry points outside the home, seal all cracks larger than 1/4 of an inch and install weather strips at the bottom of exterior doors.
• Keep your property clean, inside and out: Clean up crumbs and spills as soon as they happen to avoid leaving food residue or sugary substances that can attract rodents. Store all food (including pet food) in tightly sealed containers like plastic bins and never leave food or dishes sitting out overnight.

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