Rats allegedly as big as cats are invading people's homes, making their way inside via sewage pipes and in through the toilet.
Experts have warned that the rodents are getting "bigger and braver" after lockdown, when they were forced to look for other food sources, like homes, because restaurants were closed.
Now, a pest controller from Norwich, Norfolk has said he has been forced to take on more staff as the problem spirals out of control.
Andrew Dellbridge, boss of Ace Pest Control, told the Norwich Evening News has warned people to keep an eye on their toilets.
He said: "They used to work around us but now they’re gaining access they wouldn’t have attempted before.
"They’re letting themselves into people’s houses and businesses.
"I was called out to one job in Norwich and the customer could barely speak, she was in so much shock.
"She’d been using the bathroom and heard a noise.
"She looked down and it was in the toilet bowl. And this is happening more and more frequently."
The pest controller added that the period over winter is usually the industry's busiest, but this year they have been flat out all summer.
Luke Pomfret of Pestfree Pest Control in Grimsby told The Sun in May that he has found rats measuring more than a foot long inside people's homes.
"Restaurants are closed, but rats haven’t gone away. They follow people," he said.
Another pest controller, Chris, of We Care Pest Control Hull, added that this year he found a huge dead rat under an OAP's toilet.
The British Pest Control Association (BPCA), which represents 700 rat catchers across the country, told CNN in February that its members has reported a 51% hike in rodent activity during the first lockdown and a 78% increase in November.
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