Homes could be crawling with Britain’s most venomous spiders over the next few months.
Experts are warning this year’s mild weather, which is expected to continue through September and beyond, could help spark a bumper season for the false widow.
The UK population of the species, whose bite is typically as painful as a bee sting, has soared into the millions in recent years and is thought to be growing all the time.
Pest management consultant Clive Boase said reports of bites from the spiders were rare.
But he said: “We’ve had a reasonably warm year with very few cold snaps and no particularly extended periods of either dry or wet weather.
“That has led to more invertebrates, such as flies, to feed on and means false widows, as well as many other species of spiders, have been able to continue their development throughout the summer.
“Sightings of spiders often peak from September as males of many species reach adulthood and venture into homes in search of a mate, but we could be seeing a lot more of them than normal over the next month or two.”
False widow spiders were introduced to Britain more than 100 years ago, according to the Natural History Museum.
The species first established itself on the south coast, particularly in Dorset, Hampshire and Devon, but has significantly increased its foothold in the UK over the last 25 years.
They continue to colonise southern counties but are now becoming increasingly common in other parts of the country with sightings as far north as Scotland.
Mr Boase says climate change and the warmer conditions it brings has been a major factor in the growth of the species.
He said: “The population of false widows in the UK is growing all the time. In fact, people don’t realise just how common they have become.
“There are half-a-dozen different species of the false widow and they can survive both indoors and outdoors. They prefer suburban areas and are most commonly found around domestic and commercial premises.
“They love conservatories and toilet blocks, window frames, porches, lofts and garages and they like to live beneath kitchen appliances and cupboards.
“They are generally shy creatures and won’t come out into the open, but they could crawl into curtains or perhaps clothing left on the floor.”
While false widows have developed a fearsome reputation as Britain’s most venomous spider, reports of bites remain rare.
Mr Boase added: “They certainly can give a painful bite, but there have been very few reports of that happening as they will only do so as a last resort.
“Bites usually result from handling the spider roughly or perhaps having it trapped between clothing and skin.”
False widows, originally from the Canary Islands, can grow up to 3cm across and are distinguished by their shiny, black, bulbous bodies and markings which look like a skull on their abdomens.
They got their name through their resemblance to the deadly black widow spider, which has a nasty bite known to have been fatal to humans but which is not likely to become established in the UK, experts say.