The number of cockroaches appears to be on the rise in the Halifax area, and while experts aren’t quite sure what’s behind the population boom, the pests may be immune to some pesticides.

Leanne Langille says she has encountered several of the pesky insects in her Dartmouth apartment since moving in.

“My partner, Mason, he had one in his hair one night and freaked out, woke up, and flicked it off of him,” says Langille.

She says she has complained to the managers but, so far, arrangements for pest control haven’t worked out.

Langille isn’t alone. One couple looking to rent a condo in a seven-year-old building in Halifax was shocked when they moved the fridge and found the space crawling with roaches.

They backed out of the deal, but not before taking a video, which is going viral on social media.

Experts say roaches are remarkable, adaptable creatures that reproduce quickly and, over time, develop immunities to pesticides.

“So what happens is that you’re selecting for animals that aren’t affected by it, so you kill all the ones that are susceptible, and then you’re selecting for the resistant ones,” explains Andrew Hebda, zoology curator at the Nova Scotia Museum of Natural History.

Pest control expert Tom Hurshman says calls are up in the Halifax area, and methods of getting rid of roaches are changing.

“Back in the day you would go in and spray a residual chemical along with bait,” says Hurshman. “Now it’s known baiting and using dust is the best mode of action for eliminating a cockroach population.”

Meanwhile, Langille says the battle at her apartment is ongoing, and it’s one she feels she’s losing.

“We’re going to try to see if we can get them sprayed again and hopefully it will work,” she says.

With files from CTV Atlantic's Bruce Frisko