Rats, driven from their burrows by weeks of rain, have been invading homes in flood-hit areas.
A pest control company, based in Leatherhead, said calls about rats found in houses had more than doubled over the past three weeks.
Pest controller John McFarlane, of 6Boroughs Pest Control, said roughly half the call-outs had been to addresses in Leatherhead and Ashtead.
Mr McFarlane said: "There has been an increase. We have had quite a few calls about rats going into homes.
"The rats are obviously looking for shelter and a dry, warm environment if they are flooded out of where they usually are.
"Most rats live around houses and live in garden areas. If there is an opening to a house then they will get in to make a nest and shelter from the rest of the weather."
He said the company has received about 15 calls in the past three weeks, up from the usual one or two a week.
The company covers Mole Valley, Epsom and Ewell, Reigate and Banstead, Sutton, Elmbridge and Kingston.
Flooding in Leatherhead in January
Mr McFarlane said: "What people should be looking out for are noises of scuttering or scurrying, rat droppings and signs of chewing. They should get it dealt with straightaway."
Another company, Basis Prompt Pest Controllers has warned that further flooding could result in a "deluge of rats"
Managing director Rob Simpson said: "Infestations of rats often increase during very wet weather as flooding will flush them out and force them to find new homes.
"They will try to find some sort of dwelling to live in - it can be garages or sheds or even lofts to get away from the water and the knock-on effect is more infestations in homes."