A surge in out-of-season flea and fly infestations has been blamed on climate change.
Calls about the unwanted visitors to pest controllers Rentokil shot up during the first three months of this year compared with the same period in 2018.
While flea inquiries increased by 198%, fly infestation complaints increased by 120%.
Milder winters are causing the insects to emerge earlier to breed, Rentokil experts believe.
Some fly species use homes as dry places to hide over the winter months, before re-emerging in the spring.
This year’s February has been the warmest on record, according to the Met Office, with temperatures as high as 20.3C.
David Cross, head of Rentokil’s technical training academy, said: “There’s been a sharp increase in the number of flea and fly inquiries out of season – they are coming out much earlier than we would usually expect.
“Looking at the averages for the first quarter of the past five years, evidence suggests that our warmer climate is impacting insect breeding seasons, and it is likely to be the cause for increased calls to pest controllers.”
Flies need warmth to ready themselves for flight, and clusters of the insects emerging from winter hibernation sometimes gathered in large numbers around house windows, he said.
Warmer conditions also meant food and household waste decomposed faster, creating ideal conditions for house flies and their larvae.
Mr Cross added: “Fleas typically live outside, and far fewer of the insects have been killed off by our recent mild winters.
“With cats and dogs spending more time outside in the warmer weather, it’s likely that increased numbers of these insects were brought back into the home.
“This particular pest can be a difficult one to treat, as any fleas found on the host, both human and animal, typically represent just 5% of the total flea population nearby.
“The other 95% will be in bedding, carpets and furniture.”
He urged people to combat flies by sealing waste bins, covering left-out food, and keeping windows and doors shut at night.
Fleas could be resisted by regularly cleaning and checking pets, washing pet bedding at above 50C, vacuuming floors and furniture, and placing pet beds in areas without carpets.