Extermination companies are reporting a sharp rise in the number of rats and mice invading West Palm homes.

Palm Beach County has been especially hard hit, with areas including West Palm seeing a 30 per cent rise in complaints over last year.

Jeff Norris, owner of Nuisance Wildlife Removal, said his company is getting up to 10 calls a week about rats in houses.

“There’s a lot of mental stress involved when they have such a rodent in their home. You know when you have this animal in your house because they’re quite loud. And then there’s the big fear of them chewing on wires,” he said.

Rats chew on things to keep their teeth trim. In a house, they often chew on wires, which could spark a fire.

“Over the last year, we’re probably up 30 per cent in rat calls. There’s not one specific thing we can pinpoint it to, but the last couple of winters have been mild,” Norris said.

“We’ll hear horror stories from other people that they’re bigger than cats, but we see them in the range of 16 ounces.”

Local home improvement stores say demand for traps and poison is the highest in years.

“Some people come in an say, ‘Oh, I’ve got a rat in the house. Wife opened the cupboard door this morning and there was a rat and she’s not very happy’ — which I wouldn’t be either,” said one manager. “It’s the sheer size of rats that upsets a lot of people.”

Experts say that rat and mice populations have been rising for several years and that the recent cold snap is driving them inside human homes seeking warmth. Florida’s Norway rat is an introduced species that cannot take a lot of cold.