This article provides practical information about manure flies (Scathophagidae and other dung-associated Diptera) – how to recognise them, where they are found in the UK, how to avoid infestations, and how to control or remove them from farms, gardens, and domestic environments.
In the UK, manure flies are also referred to as dung flies, stable flies, or scavenger flies, depending on species and setting.
What do manure flies look like?
Manure flies are a group of small to medium-sized flies, usually measuring between 3 and 8 mm. They can appear yellow, grey, or dark brown, often with bristly bodies and large legs adapted for walking on waste. Some species, like the yellow dung fly (Scathophaga stercoraria), have a distinctive golden-yellow body with fine hairs.
Manure fly larvae (maggots) are pale, legless, and typically found within manure or other decomposing organic matter.
Where are manure flies found in the UK?
Manure flies are widespread across the UK and occur in rural and semi-urban areas, especially where livestock are kept. They are common from late spring to early autumn and are most active during warm and humid periods.
You are most likely to encounter manure flies:
-
Around stables, barns, and animal shelters
-
In manure heaps, compost piles, or silage
-
On pastures grazed by livestock
-
In gardens fertilised with animal manure
-
Near pet waste in urban gardens
-
Occasionally indoors, especially in homes located close to farms or manure storage areas
Their presence is often linked to poorly managed waste or high levels of organic material.
Where do manure flies live and reproduce?
Manure flies lay their eggs directly onto fresh manure or other decomposing organic material. Eggs hatch quickly – usually within 24–48 hours – and the larvae feed on the waste material before pupating. Pupation occurs either in the same material or in adjacent soil. Adults emerge soon after and restart the cycle.
Preferred breeding grounds include:
-
Fresh livestock manure (from cows, horses, pigs, poultry)
-
Moist straw or soiled bedding
-
Rotting silage or hay
-
Organic waste left in warm, damp conditions
In optimal weather, the entire life cycle may complete in 10–14 days, allowing for rapid population growth if left unchecked.
How can you avoid manure fly infestations?
Preventing manure fly infestations relies on consistent hygiene and proper waste management.
Clean animal housing regularly
Remove manure and soiled bedding from animal stalls on a daily basis to disrupt the fly life cycle. Maintain dry, well-ventilated conditions inside enclosures.
Store manure securely
Keep manure in designated areas away from housing or feeding zones. Use covered or enclosed storage to restrict access for adult flies.
Compost correctly
Turn compost heaps regularly and ensure they maintain high internal temperatures. A well-managed compost pile breaks down material quickly and deters fly development.
Avoid spreading fresh manure
Apply only well-rotted or composted manure in gardens or fields. Fresh manure can introduce fly eggs and larvae directly to the soil.
Manage pet waste
In gardens and parks, remove dog or cat faeces promptly, particularly during warmer months.
Improve site drainage
Prevent waterlogging in and around animal areas, compost zones, and waste storage to reduce the damp conditions manure flies thrive in.
How do you recognise a manure fly problem?
Signs of a manure fly infestation are often visible and may include:
-
Clouds of flies around manure heaps, compost piles, or animal bedding
-
Increased fly activity around animals, particularly near the eyes, nostrils, or wounds
-
Presence of maggots in manure or soiled straw
-
Flies entering buildings and lingering near doors or windows
-
Persistent fly populations despite general cleanliness
High numbers of manure flies not only indicate a breeding issue but can also pose hygiene concerns, especially in stables and food storage areas.
How do you get rid of manure flies?
Eliminate breeding sites
Removing or properly managing organic waste is the most effective control. Clear manure frequently and maintain clean bedding and feeding areas.
Increase ventilation
Dry, well-ventilated environments discourage fly activity. Use fans in barns and sheds to improve airflow and disrupt the flies’ movement.
Use biological control
Introduce beneficial insects such as parasitic wasps (Spalangia spp., Muscidifurax spp.) which target manure fly pupae. These natural predators can reduce fly emergence significantly.
Apply insecticides where needed
Targeted insecticidal sprays or larvicides may be used on manure piles or building surfaces. Always use products approved for agricultural or domestic use and follow all safety instructions.
Use physical traps
Sticky traps, bait stations, and UV light traps can help reduce adult fly populations, particularly in enclosed spaces or near animal shelters.
Accelerate composting
Ensure compost heaps reach temperatures that destroy fly eggs and larvae. A balanced mix of green and brown material, plus regular turning, encourages effective decomposition.
What is the life cycle of a manure fly?
The life cycle of a manure fly consists of four stages:
-
Eggs – laid on fresh manure or moist organic matter.
-
Larvae – maggots hatch within 1–2 days and feed for up to a week.
-
Pupae – develop in manure or nearby soil for several days.
-
Adults – emerge and reproduce, with each cycle taking as little as 10 days in warm conditions.
Multiple generations can occur from May through September, especially in warm, damp environments.
Can manure flies enter homes?
Yes, manure flies can enter buildings, particularly in rural areas or homes near stables and manure piles. They may be attracted to lights, food odours, or the moisture from sinks and drains.
To prevent indoor issues:
-
Install fine-mesh screens on windows and doors
-
Keep doors closed near composting or animal waste areas
-
Seal cracks around vents, pipes, and window frames
-
Use fly traps in kitchens or utility rooms
Although they typically do not breed indoors, their presence can be bothersome and unhygienic.
Are manure flies harmful?
Manure flies are not generally dangerous, but they are associated with animal waste and can carry bacteria or pathogens. When they land on animal feed, kitchen surfaces, or open wounds, they may contribute to the spread of disease.
While they do not bite, large populations are unpleasant and may cause irritation to livestock. In sensitive environments such as farms, veterinary clinics, or food processing sites, manure fly control is essential for maintaining hygiene and health standards.