A Toronto pest control company is raising the alarm about an increase in the city’s rat population.

Daniel Mackie of Green Leaf Pest Control says he’s seen a spike in cases of rodents in residential areas over the last few years.

"They like to share the same places that we do," he told CBC News. "So people will open up their cupboards, and sure enough, there's a rat sitting there chewing on a cereal box."

He says milder winters and wetter summers are creating perfect environments for breeding, while a rise in construction is disrupting rodent habitats. Composting also provides the furry creatures with an easy food source.   

Rats tend to inhabit areas near rivers or water sources, so neighbourhoods like Leslieville, the Beaches, Forest Hill and Rosedale have been most affected, Mackie said.

Rodents can carry 50 different kinds of illnesses, according to health officials.

"I describe the rodent activity in Toronto as a low-level, smouldering kind of infestation," says Reg Ayre, a spokesman for Toronto Public Health.

The agency only responds to complaints of rats in restaurants — not residences — but ​Ayre says there hasn’t been a spike in cases in those establishments.