SUSPICIOUS smells of vomit hanging around houses and kitchens this summer could be down a nasty infestation of drain flies, experts have warned.

The tiny fuzzy moth-like insects breed in sinks when the conditions are right and the weather heats up — and are known to smell like vomit when in clusters.

Generally, they are billed as harmless, but because they tend to spawn in filthy surroundings specialists at 24/7 Home Rescue warn they have the potential to transmit harmful bacteria too.

And like many unnerving critters, the warmer months of the year they can strike and lay up to 200 EGGS at a time.

"A simple flush of the toilet can be enough to spark a trickle that provides the perfect breading ground for them," says property maintenance and plumbing expert Ranjen Gohri from 24/7 Home Rescue.

"To keep them in order you need to deny these little pests the source of water. Insect spray can also be used to deter them.

"Other ways include traps which can be hung up, solid-block insecticides and ultra-violet electric killers that zap them."

"You can have several thousand flies all clustering together. This is when they start to produce a smell similar to vomit.

"If they're fizzing around the place they can easily drop into your food and you may not notice as they're much smaller than a regular household fly, usually less than 2mm in length."

Damp murky environments such as soggy food bins are also ideal hangouts for multiplying, along with slimy plug holes and leaky toilet pipes.

Sewer flies, as they are also named, are known to breed like crazy, generating their vomit-like smell.

As the UK enters its summer months, infestations are likely to occur in blocked drains and gutters. Indoors, check any source of standing water like plant pots where they also like to hangout.

And very little water is needed for drain flies to lay eggs. Even a tiny trickle from a pipe joint can cause the problem.

Other signs you may have drain flies include tiny black worms turning up inside and round the opening of your sink or bath plug hole.

Ranjen Gohri added: "These black worms are actually drain fly larvae.

"If you're not using your sink very often and water is left standing in the pipes it will attract drain flies to lay their eggs, up to 200 at a time.

"When they hatch you'll see little worm like creatures less than a centimetre in length. They thrive on soap scum and sink residue. "​ A cluster of adult flies may become so populous they'll congregate at windows if there's condensation, around showers, bathtubs, sinks and floor drains, warns Ranjen.

"And they can be a right pain for human openings too, getting into the eyes, ears and noses of people," he said.

"Since these flies originate in filthy conditions, there is also the possibility of physical transmission of germs which could potentially make a human ill."

Ranjen's tips for getting rid of drain flies naturally: "Pour some apple cider vinegar into a glass and cover with cling film. Make holes into the cling film and place the glass next to the sink. The vinegar will attract the flies who will find their way into the glass and drown as they're rarely smart enough to find a way back out."

"A metal pipe brush pushed backwards and forwards followed by a flush of boiling water will dislodge any fly clusters in the pipes."

"Why not make a trap by putting a bowl of equals measures of sugar, water, white wine vinegar and five to ten drops of washing up liquid. Leave the bowl overnight and see how the flies will be attracted to the liquid and meet their fate by drowning."

"Dehydrate them by pouring a good scoop of salt, baking soda and vinegar down the drain. Let the mixture sit overnight. In the the morning pour a pot of boiling water down the plug to wash the flies away."