FREE Delivery On All Orders Over £250 - Conditions Apply

Supplying the poultry industry for three decades

How To Know Which Type of Flies You’re Trying To Control

Rowan Burgess |

Do you know which flies are common on your farm? Flies cause various problems on the farm depending on what type of animals or birds you have. 

Fly species feed on different things, depending on the type and species. Their habits and lifestyle vary, as do the methods used to control them. Fly prevention methods include cultural control, excellent animal husbandry, and proactive insect management protocols during the main fly season. We could keep going!

Let's start by learning to identify the different flies, a crucial first step in successful fly control and insect management.

Types of Flies in the UK

Bluebottle Fly


An interesting name! We call them bluebottle flies due to their distinctive metallic blue colour. These flies are around 5-8mm in length and similar in size, if not slightly larger than the common housefly.

Bluebottle flies are also simple to identify, as they have large red eyes and transparent wings. They're pretty noisy, fast flyers and easily differentiated from houseflies with more solid bodies.


Bluebottles live outside during the summer month - a problem for any farm. However, during the winter, these pests make their way inside buildings for warmth and a possible food source.

It’s not a nice thought, but bluebottles are fond of decaying flesh, so animal remains are a natural attraction. Faeces and general farm waste also attract them.


It's essential to follow good hygiene practices on your farm, regardless. If you see bluebottles congregating, search out the possible source of attraction. A dead rat or mouse is a favourite meal on a livestock or poultry farm.

Use electronic fly killers and traditional methods like fly glue strips on a roll to catch bluebottle flies in the height of the summer. Physical barriers like meshes, screens, and chain fly curtains work well in specific locations - depending on the building style and the livestock.

Clean and disinfect animal housing when empty and pay particular attention to nooks and crannies, where bluebottles head in the winter to hibernate, seeking warmth and food. Then, destroy the larvae and reduce the adult fly population the following spring.

Cluster Fly


Cluster flies are 6-10mm long but have larger bodies than a standard housefly. They have long wings which overlap when they are at rest - which is different to other fly species.

A cluster fly is a dark grey colour. The flies are identifiable by their thorax, an olive-grey colour covered with fine golden-brown hairs. They're also easily identified via patches of gold hair on their wings and back.


Cluster flies are found outdoors in the summer months. During the winter, they're attracted by light and warmth. You may see them at height in animal housing if there's a window or light source, just as they favour attics in domestic properties.

Cluster flies lay their eggs outside but are attracted to farm buildings when it’s cold so they can hibernate. They'll typically return year after year unless effectively controlled.


Electronic fly killers and traditional fly traps capture cluster flies if they hang around livestock yards and animal housing during the warmer months. Cluster flies live in hard-to-reach areas, so disinfection protocols should be rigorous when housing is empty. 

Always use a proprietary insecticide to destroy any fly colonies or larvae. They're often hidden high up in roofing, in inaccessible locations. Therefore, smoke bombs are highly effective on cluster flies and useful for sudden infestations.

Fruit Fly


Fruit flies are one of the smallest flies you will find around the farmyard - or in your kitchen. They’re only around 3mm in length, and they have a black abdomen which is coloured grey underneath. This abdomen hangs down low, making their flight time slower.

Their thorax is a light yellow or tan colour with transparent wings, and fruit flies have large red eyes.


Fruit flies are attracted to food, including animal fodder. This can be in storage areas, locations with food, and refuse bins and drains. Fruit fly larvae feed on the fungi found in decaying food, so it won’t be sufficient to destroy the adult flies; the larval site must also be identified and removed.


It’s crucial to keep animal feed securely stored in sealed bins which are vermin and flyproof. Clean eating areas daily to clear up old residues; anything fermenting or going rotten in the heat is a big attraction. Manage waste disposal so that it doesn’t encourage fruit flies to congregate.

Large populations of adult fruit flies can be controlled in the warmer months using a residual insecticide or ULV method (Ultra-low volume), also called cold fogging. Using a spray with a low volume of a proprietary chemical can treat a large area.

Filter Fly


The adult filter fly is 2mm in size with almond-shaped wings. The filter fly has a hairy body, although this is not always easy to see due to its size. Filter flies have an easily detectable flight as they're weak fliers. They often appear to be jumping or hopping.


Rotten vegetation, manure, dung, and all organic matter attract filter flies. Their lifecycle is rapid, just two weeks in optimal conditions, although other fly species are faster than this.


We recommend deterring filter flies with suitable year-round pest control methods, not just in the spring and summer.

Good yard hygiene and managing food spoil and manure will minimise the volume of filter flies. Adult populations can be controlled with long-residue insecticides and physical devices such as baited fly traps, glue strips and screens. 



Houseflies are grey with four clear black stripes on their thorax. They are 4mm-6mm long and have a small amount of hair on their bodies. 

Houseflies have large compound red eyes and far-reaching vision. They don't bite or sting, so aren't equipped with teeth or a stinger. 


The housefly has a four-phase lifecycle that lasts only six days from egg to full-grown adult in optimal conditions. Houseflies don’t have teeth, so they only feed on liquids, but they use spongy mouthparts to pulverise many solid foods into a liquid state.

Houseflies have a varied diet, so there's plenty around the farm to keep them well-fed, and busy, and we’re not just talking about the animals. They're particularly attracted to manure because of its strong smell.


About 80% of a housefly’s existence is invisible to the farmer - that is, the laying of eggs, hatching into maggots, and hibernating in pupae before becoming a fully grown flying insect.

The most effective measure to prevent houseflies is making environmental changes to discourage them from breeding in the first place. This method is called cultural control

The aim here is to organise the farm and animal management in a way that is as unfriendly to the flies as possible. We recommend tackling fly control in the autumn and winter when the flies are still present, just not visible.

Insecticides and physical fly control products like electrical devices and glue traps reduce active housefly populations in the height of the insect season in spring and summer - both in the yard and where the animals congregate. Topical treatments like sprays and ear tags minimise houseflies' impact on livestock.

Horse Fly


Horse flies have a grey/brown body and a robust and persistent flight, especially with a meal in their sights. Horse flies are larger than houseflies and bluebottles, at anywhere from 10mm to 30mm in length. They have large green or purple eyes with horizontal stripes.

Their bodies are hairless and without bristles, and they have six legs.


Although horse flies certainly plague horses, they also turn their attention to other mammals and are particular pests for cattle. Horseflies tend to focus on dark, moving objects, so dark-coloured cattle or horses can be driven to distraction and become distressed trying to avoid them.

Horse flies have mouthparts that can tear and slice, making their bite painful. Interestingly, only female horse flies attack cattle, horses - and people! - and draw blood. Once a horse fly has bitten, it'll stay latched on unless the animal can remove it via its head or tail or brushing against another animal or fence. They'll eventually drop off when they've had enough.

Professor Tim Caro, an Honorary Research Fellow from the University of Bristol’s School of Biological Sciences, has studied zebra stripes for years. He discovered, almost by accident, when studying a domestic zebra herd and horses dressed up to look like zebras, that the stripes confused horse flies, and a whole generation of zebra-striped fly rugs was born for horses! Previously, rugs had been white.


Horse flies have a short biting season from around June through to August, but when they're about, they cause real distress to animals which, in turn, impacts yields.

Horse flies breed in wet soil near bodies of water where livestock also tends to congregate. 

We recommend managing them with active fly control in animal housing and livestock areas.

A good farm layout can help reduce the breeding potential of the horse fly. 

Autumn Fly


The female autumn fly is almost identical to the housefly and is around 6mm-7mm in length. However, the males are different, with an orange abdomen and black stripes - much smaller than the females.

The autumn fly has large red eyes and transparent wings. 


The autumn fly is easy to spot around the eyes and noses of cattle and horses, where they're attracted by moisture and saliva and obtain protein. The animals’ manure also encourages them.


Physical barriers work well with autumn flies, such as screens, meshes, or fly veils on the animals. They're less common on cattle in the UK but seen on horses.

Remove autumn flies with electric fly killers and insecticides. Spraying and cold fogging is an option throughout all seasons to control fly numbers.

Frequently Asked Questions

What Is the Most Common Type of Fly in the UK?

The most common type of fly in the UK is the housefly, a seasonal pest in domestic and commercial premises, as well as farms and agricultural businesses.

With the impact of global warming, the housefly season is extending, starting earlier in the year and often continuing through to November.

Final Thoughts

Find everything you need to control all the different fly species at Dalton Engineering, specialists in insect control and prevention. We stock a comprehensive range of insecticides and sprays, plus physical fly traps, electric killers, screens and meshes, supporting UK farmers to provide the best animal husbandry, welfare and farm yields.

Trust Dalton Engineering, your professional agri-partner.