Snakes that are kept as pets have been escaping in increasing numbers as the weather gets hotter, according to zoologists.

The rising summer temperatures might be good news for many, but for those suffering from ophidiophobia — a fear of snakes — the heatwave is not a cause for celebration.

One woman in Acton, West London, discovered a brown corn snake on her landing late at night, before it slithered into her bathroom. It then reappeared a few days later before being captured.

Last Friday police were called to a house in Lee-on-the-Solent, Hampshire, where a 3ft king snake had been found, and a Haitian boa was discovered coiled up on a doorstep in Basildon, Essex.

Because snakes are cold-blooded animals, they need to sunbathe to warm up and stay active, and they also need the ultraviolet rays in strong sunshine to make vitamin D, essential for their health. If the snakes were well fed before escaping, they can stay hidden in cavities — cupboards or behind plumbing — for up to a year before they need to search for food.

Mark Amey, who runs a zoo near Watford, Hertfordshire, receives a steady stream of escaped snakes rescued by the RSPCA. “I’m getting around two snakes a day, mostly corn snakes and rat snakes, because this is brilliant weather for them, over 28C,” he said. “And the thunderstorms help because the heavy showers flush out mice or rats that they can eat.”

Last year the RSPCA received 586 calls about escaped snakes, most of them in summer and early autumn, and the number this year is expected to be far higher. “We strongly advise anyone who discovers a snake to be extremely careful and leave it alone, bearing in mind that it could be deadly,” Jude Clay, of the RSPCA, said. “They should alert neighbours and call the appropriate local authority’s environmental health department or the RSPCA on 0300 1234 999.”

Other dangerous animals have also been appearing in the heat. “There have been reports of escapes of caymans, which are related to alligators, the fire belly salamander, which has highly toxic skin, and the rare spiny-tailed iguana,” according to Ian Newby at the Dangerous Wild Animal Rescue Facility.