Fly control in London

The six we see most:

• House fly: 6 to 7 mm; egg to adult in seven to ten days when warm; up to 500 eggs per female in waste and carcasses
• Bluebottle: 10 to 14 mm, metallic blue; two weeks on decaying meat, so indoors it means a dead rodent or bird
• Cluster fly: about 7 mm; larvae parasitise earthworms, so breeding cannot be disrupted; adults enter roof spaces from September
• Fruit fly: about 2.5 mm; egg to adult in 8.5 days at 25°C; around 400 eggs per female in rotting fruit
• Drain fly: hairy, moth-like; eggs above the water line in a drain hatch within 48 hours; larvae feed in the sludge for 9 to 15 days
• Fungus gnat: 2 to 8 mm; eggs in wet potting compost; adults live up to 10 days

Removing the source is the only treatment that lasts. A professional-use residual insecticide on resting surfaces holds adults down for weeks; fogging clears heavy numbers in hours but leaves nothing behind, so it is never used alone. Drain treatments strip biofilm; fly killers and screens stop the next generation. Loft work follows BPCA's cluster fly guidance and starts with a bat check.

The price moves with the species and the breeding site. A bluebottle job is one visit if the carcass is reachable, more if a floor or wall must be opened. Drain flies need the sludge physically removed, so drain cleaning or jetting is the main cost, plus a follow-up visit. Cluster flies are priced by loft size and how much of the eaves can be sealed. A food-business quote covers fly killers, tube changes, door screens and the service record.

No council figure exists to compare: neither Kensington and Chelsea's charge list (updated 9 July 2026) nor Hounslow's (from 1 April 2026) includes flies. The inspection survey is free, the quote is fixed in writing and there is no call-out fee.

Before we arrive:

• Note where the flies gather and when they started; bluebottles in one room point us to the void
• Do not pour bleach down a plughole with drain flies: it runs past the sludge they breed in
• Empty indoor bins and take the waste out; never leave waste inside overnight
• Clear the loft hatch and tell us if bats have ever been seen in the roof

Afterwards:

• Keep the treated room clear for the time stated on the product label
• Adults die off within days once the source is gone, but eggs already laid still hatch, so drain fly stragglers for two weeks are normal
• Fruit flies restart in about 8.5 days from one missed bin, so the waste routine matters more than spray
• If activity continues beyond two weeks, call us: the six-month guarantee, subject to survey, covers a return visit

In a rented home Shelter's rule is cause-based: disrepair or a pre-existing infestation is the landlord's, pests the tenant's own conduct caused are theirs. Awaab's Law Phase 2 (30 November 2026) covers social landlords only, with pests under fixed timescales in Phase 2 or Phase 3 at the latest; private renters are not yet covered. Councils have no duty to treat flies: the Prevention of Damage by Pests Act 1949 covers rats and mice only.

A food business carries the duty itself: Annex II of Regulation 852/2004 requires adequate procedures to control pests, enforced under the Food Safety and Hygiene (England) Regulations 2013. In 2016 Leeds City Council prosecuted a food store over flies, a fly killer tray full of dead insects and no pest control evidence: a £1,500 fine plus £2,500 costs. A rating of 5 needs no element scored above 5, and pest control sits in the structure element, so flies alone can cap it. Bromley Council's siting rules apply: no fly killer above a food preparation surface, none visible from outside.

Cluster flies follow lofts, so those fly pest control calls come from the Victorian and Edwardian terraces of Chiswick, Wandsworth and Wimbledon and the TW postcodes around Hounslow and Richmond, with big roof voids and gardens full of earthworms. Drain and fruit flies belong to the converted houses and mansion blocks of Kensington, Earl's Court and Kilburn, where flats share a stack and a bin store. The commercial work is the West End: restaurants and bars in Soho, Mayfair and Marylebone, for fruit flies behind the bar and fly killer siting. We cover central, west, north-west, north and south-west London and the TW postcodes.