Flies can be irritating little creatures that buzz around your head and your food, and taking a swipe as one passes seldom works. They're more than just a nuisance, too: house flies and bluebottles can carry bacteria such as salmonella, typhoid and E. coli, picked up from drains, decaying matter and animal faeces.
The single biggest mistake we see is treating every fly the same. A house fly, a fruit fly and a cluster fly can look like one problem, but they're three different problems – and the fix that clears one will do nothing for another. Almost always, success comes down to the step people skip: hunting down where the flies are actually breeding and dealing with that, rather than just the flies you can see.
This guide shows you how to tell the common UK flies apart, match the right control to each, and get rid of them yourself – quickly, safely and cost-effectively.
📋 Quick summary: getting rid of flies
- Identify first, then find the source – the three common flies (house/bluebottle, fruit, cluster) need different fixes, but for all of them you deal with where they're breeding, not just the adults you can see.
- House & bluebottle flies – a hygiene and waste problem: bins, drains and fly screens first, then fly traps, electric fly killers and fly killer sprays.
- Fruit flies – remove the breeding source (over-ripe fruit, drains, recycling); a fly trap clears the adults, but sprays alone won't fix it.
- Cluster flies – an autumn loft-invader, not a hygiene issue: seal entry points with insect-proofing, then window traps or a roof-void treatment.
- Act fast either way – flies breed quickly, so a few can become an infestation within a week or two.
Common Types of Flies
The most common fly is the housefly, found all over the world. Reassuringly, of the 120,000 fly species globally, only a few are found in the UK. Here are the ones you're most likely to meet.
House Fly
The common house fly is found across the world, anywhere there is rubbish and animal faeces. It's the most common fly in the UK and the one you're most likely to see indoors. House flies are usually grey to black, with a yellow abdomen, a striped grey thorax, large red eyes and pointed wings, and a covering of fine hair.
Bluebottle Fly
Bluebottles look similar to houseflies but have a metallic blue colouring. They're common in and around the home, feeding on dead creatures, animal faeces and your food, and they particularly like rotting meat and carcasses, where they lay their eggs. The larvae feed on the decaying matter, then pupate away from it before emerging as adults.
While they aid natural decomposition, they're serious disease carriers, spreading bacteria like salmonella and E. coli. Good hygiene and proper proofing are the priority, and insecticides are often not the appropriate treatment.
Autumn Fly
Similar to the house fly, the male autumn fly has an orange abdomen with black stripes and is smaller than the female. Both have large red eyes and clear wings, and they're usually found around the eyes and noses of cattle and horses rather than in homes.
Cluster Fly
Cluster flies get their name from their habit of gathering in large clusters in roof voids. They're generally larger than houseflies, with a dark olive-grey thorax covered in golden-brown hairs and wings that overlap when at rest, and they're noticeably slow and sluggish.
Crucially, cluster flies are not a hygiene pest. They lay their eggs in soil, and the larvae burrow down to feed on earthworms, so they don't breed in your home, bins or food. Adults live outdoors through the summer, but as the weather cools they push indoors for shelter, living in nooks and crannies – which makes them a major nuisance from late autumn to early spring.
Fruit Fly
Noticeably smaller than the others, fruit flies have an abdomen that's black on top and grey underneath, a light yellow to tan thorax, large red eyes and transparent wings. Their abdomen hangs downward, which makes their flight slow and hovering.
Which Fly Is It – and What Actually Works?
Before you reach for a spray, work out which fly you're dealing with, because the right fix depends on it. The two we're asked about most are fruit flies and house flies, but cluster flies catch a lot of people out every autumn. Here's how to tell them apart and what works for each.
| Fly | How to spot it | Where it's coming from | What actually works |
|---|---|---|---|
| House & bluebottle flies | Familiar fast, buzzing flies; bluebottles are metallic blue. | Bins, drains, decaying matter, animal waste. | Sanitation first – sealed bins, clean drains and surfaces, fly screens. Then UV fly killers, sticky papers and targeted sprays for the adults. |
| Fruit flies | Tiny (2–3mm), slow, hovering around fruit, bins, drinks and drains. | Over-ripe fruit, fermenting liquids, recycling, damp drain residue. | Remove the breeding source – bin over-ripe fruit, clean drains and recycling. Sprays and zappers alone won't fix root cause but can help. |
| Cluster flies | Like house flies but larger, darker and sluggish; appear in big numbers at upstairs windows and in lofts in autumn. | Not your bins – they breed in fields and invade to hibernate. Not a hygiene problem. | Hygiene won't help. Seal entry points (soffits, eaves, around tiles, vents, window frames) and treat the roof void, or vacuum the clusters. Check for bats first – it's illegal to treat where bats may be present. |
Fly Behaviour
How Do Flies Eat?
Most flies, including the house fly, can't bite. Instead they produce enzyme-rich saliva, which they regurgitate onto food to break it down until it's digestible, sometimes stamping their feet in the liquefied food before sucking it all up through their proboscis. During this process they can transfer bacteria from their stomach and feet – salmonella, typhoid, E. coli and the eggs of parasitic worms – which is why they're a genuine contamination risk, not just an annoyance.
Do Flies Bite?
Fortunately most flies, including the common house fly, can't bite – they feed by sucking up food through the proboscis. A separate group of UK flies do bite, however, including mosquitoes, black flies, horse flies and stable flies.
How Long Do Flies Live?
Adult house flies live an average of 15 to 30 days, depending on food availability. Deprived of food, young flies will die within two to three days.
What Is the Fly Lifecycle?
Flies undergo complete metamorphosis: eggs become larvae (maggots), then pupae, then adult flies. You won't see many house flies in winter, as they're in their larval or pupal stage, hiding in safe spots such as compost or rubbish heaps.
In warm conditions a house fly can complete metamorphosis in seven to ten days, producing up to 20 generations a year. One female lays up to 500 eggs over a few days, in small piles, and the eggs need to stay moist to hatch. Bluebottles take around two weeks to reach adulthood and lay their eggs in rotting matter – but also on food, so keep food covered and don't eat anything flies have had access to.
Cluster flies are the odd one out: they lay eggs in soil and their larvae develop inside earthworms, so they're sluggish fliers that turn up in large numbers only when they come indoors to overwinter in roof voids. Fruit flies reach adulthood in seven to thirty days and breed in fermenting matter – fruit and vegetables, spillages and unclean drains.
Identifying Signs of a Fly Infestation
A couple of flies in the kitchen doesn't necessarily mean an infestation, but it's worth being vigilant – prevention is better than cure. Look out for clusters of small, dark spots on lampshades and surfaces, and check open drains, gaps in walls or floors, and bins. If you find maggots around bin areas, it's time to act.
Depending on where they've been, flies may carry typhoid, cholera, eye infections and dysentery, so it's worth taking action to stop flies coming into your house early.
Preventing Flies in Your Home
Don't Allow Warm, Damp Conditions
Flies are drawn to warm, moist environments, which give them ideal breeding grounds and easy access to decaying matter. Common problem areas are kitchens, bathrooms, compost bins and drains. To make your home less inviting:
- Fix leaks promptly and wipe up water spills.
- Keep damp areas well ventilated to lower humidity.
- Empty and clean compost bins and food waste caddies regularly.
- Don't leave damp dishcloths or sponges lying around.
Hygiene Tips
Keeping flies away is easier than getting rid of them, and hygiene is central to it:
- Store food in containers or the fridge.
- Keep kitchen and pantry surfaces clean.
- Clean appliances and the surfaces beneath them.
- Wipe up spillages on floors as they happen.
- Cover bins with tight-fitting lids, empty them regularly, and clean them with a strong disinfectant.
- Site bins away from doors and windows.
- Clean drains regularly with disinfectant.
Fly Screens
In summer, fit magnetic fly screens to windows – they're inexpensive, effective and easy to remove for cleaning and winter storage. Screen doors are worth it if you live near farmland or other fly-prone areas; retractable, sliding or hinged options all fit common door frames. The tighter the mesh weave, the fewer flies get through, though a very tight weave can spoil the view, and since flies aren't tiny you don't need to go to extremes.
DIY Fly Control Methods
There are plenty of ways to deal with the adult flies you can see. Our best-selling fly products are all on the lower-risk end, which is exactly where we'd suggest starting: Eradisect fly trap bags for outdoors, window fly-trap stickers for kitchens and conservatories, and Organisect, a pesticide-free spray. Reach for stronger chemicals only if these aren't enough.
UV Wall-mounted Fly Killers
Wall-mounted fly killing machines use a blue fluorescent light to attract flies; when they touch it they're zapped and fall into a tray below. Effective and easy to clean, which is why you'll often see them in restaurants and other hospitality venues.
Fly Paper Strips
These hanging strips attract flies with their scent; once a fly lands it sticks and can't escape. They're cheap, easy to dispose of, and worth replacing every couple of days.
Electric Fly Swats
A battery-operated racket you swipe as a fly passes. It makes a sizzling noise as the fly is zapped, but it works and leaves no mess.
Bait Fly Traps
Bait traps hold a lure in the base; once a fly enters and feeds it can't get out. Just empty and re-bait when needed. They get unpleasant, so hang them in a tree a good distance from the house and any outdoor seating.
Homemade Soap Mixture
A simple homemade option: leave an open jar of water and washing-up liquid in a convenient spot. Flies are drawn to it but can't fly off once they land on the soapy surface.
Natural Deterrents
Flies dislike strong-smelling plants such as lavender and basil – a pot of basil on the windowsill works as a deterrent and as a cooking herb. Plant lavender, marigolds and nasturtiums outdoors to deter flies and other pests. Citrus also helps: make a pot pourri from citrus peel and essential oils such as eucalyptus, peppermint or lavender, and wipe surfaces with the oils too.
Ultrasonic Repellents
Ultrasonic plug-ins emit a high-frequency sound and are sometimes used as an extra, background layer of deterrence. We wouldn't rely on one as a standalone fly solution, and they aren't suitable in homes with pets, whose more sensitive hearing may be disturbed by the sound.
Getting Rid of Fruit Flies
Fruit flies are the one where killing the adults you can see gets you nowhere – you have to remove what they're breeding in. Bin or refrigerate over-ripe fruit, run the bin out, rinse recycling before it sits, and clean any drain or plughole where a film of residue builds up. To clear the remaining adults, set a simple trap: a little apple cider vinegar with a drop of washing-up liquid in a glass, or a shop-bought fly trap. Sprays and zappers alone won't solve a fruit fly problem while the source is still there.
Getting Rid of Cluster Flies
Cluster flies are a different job entirely. They don't come for your food or bins – they invade in autumn to hibernate, gathering in large numbers in lofts, roof voids and upstairs windows, so hygiene measures won't touch them. In autumn we see a lot of them, and we always steer people toward the gentler methods first, for health and safety reasons:
- Seal the gaps they get in through – around soffits, eaves, tiles, vents and window frames – with suitable insect-proofing products or exterior sealant.
- Vacuum up the flies you can reach in the loft or at windows, and empty the bag outside.
- Use window fly-trap stickers to catch them as they gather at the glass.
Treating the roof void with a space spray or fogger is a later-step option for heavy infestations, but it carries real precautions (see the safety note below), and one rule is non-negotiable: if there's any sign of bats in your loft, you must not use insecticide there, as bats are protected by law. Cluster flies also tend to return to the same building year after year, so the sealing is the part that pays off long-term.
Chemical Solutions for Fly Control
Chemical fly products include fly killer sprays – knockdown sprays, insect growth regulators, residual surface sprays and foggers. Used correctly they can quickly reduce adult fly numbers, especially alongside good hygiene and proofing. Where possible, start with lower-risk options such as traps, screens and targeted, non-residual sprays. If you do use an insecticide, always read the label, follow ventilation and re-entry guidance, and keep products well away from children and pets. Anyone with asthma or sensitivities should take extra care and consider non-chemical methods first.
Fly Sprays
Fast knockdown sprays kill flying insects on contact, but they're best used as a spot treatment and with care around food-prep areas, people and pets. We personally recommend pesticide-free insect sprays where possible, such as Organisect.
For longer-lasting control, residual insecticide sprays can be applied to fly resting spots (window frames, around bins, or other landing areas where the label permits). Once dry, they leave a thin active deposit that keeps working on flies that land there later. For ongoing problems, focus first on cleaning, waste management and removing breeding sources, then combine that with targeted adult control. Insect growth regulators (IGRs) are usually a specialist option for treating breeding sites and larval habitats where labelled, rather than a primary treatment for adult flies in a typical home.
Fly Foggers
Foggers release all their insecticide at once, usually over about two hours. Use them in an open room, at least six feet from gas or electrical appliances, never in enclosed spaces such as under tables or inside cupboards, and store food in airtight containers first. Shut all doors and windows, set the fogger down, activate it and leave the room straight away, closing the door behind you. Stay out for the stated time, then open up and air the room thoroughly before going back in. Always research the product first and take every precaution.
⚠️ Using fly sprays and foggers safely
Read and follow the label every time – it's a legal instruction, not a guideline. Ventilate the room, keep children and pets away until surfaces are dry, and never spray near food, food surfaces or open packaging; take extra care if anyone has asthma. Foggers fill the whole room with insecticide, so clear out people, pets and food first, keep them away from flames and electrics, leave for the stated time, then air the room thoroughly. One UK rule for cluster flies in particular: if there's any sign of bats in your loft, do not use insecticide there – bats are protected by law, and you'll need to call a professional.
When to Call in a Professional
Most fly problems are well within reach of DIY, but it's worth calling a professional if:
- flies keep coming back after you've cleaned up and removed the breeding source;
- you have a heavy cluster fly infestation in a loft that's hard to reach or unsafe to treat yourself (especially if bats may be present);
- you can find maggots but not the breeding site they're coming from; or
- it's a food business with hygiene and compliance obligations.
A pest controller can locate hidden breeding sites, treat roof voids safely, and set up a plan for recurring problems – cluster flies especially, as they tend to return to the same building each year.
FAQs: getting rid of flies
Why have I suddenly got loads of flies?
Usually there's a breeding source nearby – a bin, a drain, a dead animal in a cavity, or over-ripe fruit – or, in autumn, cluster flies coming indoors to hibernate. Find and deal with the source rather than just swatting the adults.
How do I get rid of fruit flies?
Remove what they're breeding in – over-ripe fruit, drains, recycling – and set an apple cider vinegar trap for the adults. Sprays alone won't fix it while the source is still there.
Why do I get loads of flies in one upstairs room?
In autumn that's the classic cluster fly sign – they gather in warm, sunny upstairs rooms and lofts to hibernate, not because of any mess. The fix is sealing their entry points and treating the roof void, not cleaning.
Are cluster flies harmful?
No – they don't bite or spread disease, and they aren't a sign of poor hygiene. They do gather in big numbers, though, and dead ones left in a loft can attract carpet beetles.
Do flies bite?
Most common house flies don't. The biters are a separate group – horse flies, stable flies, mosquitoes and black flies.
How quickly do flies multiply?
Fast. One female house fly can lay up to 500 eggs, and in warm weather the cycle completes in about a week – which is exactly why it pays to act early.
Final Thoughts
When you notice a lot of flies in your home or garden, don't wait to see whether it becomes a problem – at the rate flies breed, you can have an infestation within a week or two. Work out which fly you've got, then match the fix: hygiene and waste control for house flies and bluebottles, removing the source for fruit flies, and sealing and roof-void treatment for cluster flies.
Deter them with strong-smelling plants, herbs and essential oils, don't leave food lying around, and keep bins, cupboards, surfaces and drains clean. Use a fly spray if you need to and, in extreme cases, a fogger – with all the precautions above. If you live on a farm, turn over any manure or compost heaps now and then to disturb and dry out the eggs before they hatch.
At PestBuddy, we're here to empower you with effective, fast and easy-to-use DIY fly control products. Explore our range to take control of your pest problems with confidence.
