Rats in the garden, the bins and the drains: London's rat problem and what a drain survey finds

Rats in a garden in London almost always come down to two things: a food supply, which means bins, food waste, compost or bird feed, and a route, which in this city is usually a drain. Brown rats live in the sewers and come up through a cracked pipe or a disused connection, then settle under decking or a shed because the bins are close. A treatment that only puts bait down the garden fails twice over: open-area use of the strongest poisons has been unlawful since January 2025, and the rats come straight back through the same pipe.

Why do London gardens get rats?

Because gardens offer food and cover, and a city of takeaways and communal bins offers more of both. When the National Pest Technicians Association surveyed its members in autumn 2025, more than half blamed waste and food availability: overflowing bins, inconsistent refuse collection, takeaway waste, and recycling and composting areas. The same survey found rat activity up 38% nationally, the usual autumn drop in numbers delayed by mild, wet weather, and rats active outdoors into October. One line from it sums the problem up: "We do not have a rat problem; we have a people problem."

Westminster City Council's rat leaflet lists where they settle: burrows in compost heaps, grassy banks and under sheds, and nests in lofts, wall cavities, cellars and under floorboards. Its prevention advice is short: keep drain inspection covers in place and in good repair, do not over-feed the birds, and store food waste in sealed containers, including compost bins.

Councils also had to start weekly food-waste collections from most homes by 31 March 2026 under Simpler Recycling. Nobody has yet shown whether the caddies add to rat pressure, but one with a loose lid by the back door is a feeder, so treat it like a bin.

Which London boroughs report the most rats?

Camden, by a distance, in the council data released so far. A freedom of information study by a drainage firm collected rat reports from UK councils for 2023 to mid-2025, 518,240 in all. The Evening Standard's borough breakdown of the same data put Camden first on 9,133 reports, then Islington 6,567, Brent 6,523, Kensington and Chelsea 5,740, Hammersmith and Fulham 5,382 and Haringey 3,278; Hounslow logged 991 and Kingston 272, the lowest in the capital.

Two caveats. These are reports to councils, so a borough with no service or no records looks rat-free when it is not: 13 boroughs, including Richmond and Westminster, gave no data. And the first London total of 118,593 was inflated by Southwark counting visits rather than infestations; corrected, it is about 76,500. Camden's figure still works out at roughly ten reports a day.

Why are the drains the usual route?

Because the sewer is where London's rats live, and a defect in your drain is a door. Westminster's leaflet notes that brown rats are "also found living in sewer systems" and that burrow entrances turn up "at the end of paving or drain cover surrounds"; Wandsworth Council offers drainage surveys "to check whether rats enter via the drainage system".

The faults a drain survey finds are mundane: a cracked or displaced pipe under the patio, a connection left open when a kitchen was moved, a redundant soil pipe from an old outside toilet, or a chamber with a broken cover. A CCTV survey puts a camera through the run and records where the pipe is breached and whether rat runs lead to it. The fix is a repair, or a non-return valve, often called a rat flap, that lets waste out and nothing in.

What are the signs of rats in a garden?

Burrows, runs and droppings along a wall or fence line, because rats use regular runways rather than open ground:

• Burrow holes with a fan of fresh earth beside paving edges, sheds, decking and drain surrounds.
• Worn runs along fences and walls, with the dark grey smears left "by repeated contact with rat fur".
• Droppings up to 12mm long and tapered at both ends, far larger than the 3 to 6mm of a mouse.
• Gnawing on bin lids, shed doors and cabling: rats gnaw continually to wear down their front teeth.
• Footprints and tail swipes in dust or mud.

Are rats in the garden a health risk?

The main one is leptospirosis, which is rare but worth knowing about if you garden or have children and dogs on the lawn. The NHS says it spreads through the urine of infected animals, rats and mice among them, via soil or fresh water that gets into the mouth, eyes or a cut. Most people have no symptoms or a mild flu-like illness; a few become seriously ill.

The UK Health Security Agency recorded 115 cases in England in 2025, and of the 32 with exposure details, ten involved contact with rodents or their droppings. Cover cuts with waterproof plasters, wash hands after gardening, and do not touch a dead rat bare-handed. Seoul hantavirus is carried by wild brown rats here, but the UKHSA calls cases occasional and the public risk very low.

Do I have to tell the council about rats?

If they are present in substantial numbers, yes, in writing. Section 3 of the Prevention of Damage by Pests Act 1949 places that duty on the occupier, and section 2 requires every council to keep its district free of rats and mice. Under section 4 the council can serve notice on the owner or occupier requiring treatment or structural works, and under section 5 it can do the work and recover the cost if the notice is ignored.

Reporting is not the same as getting treatment: Richmond has no pest service and Westminster is not taking private work, while Hounslow charges £155 for garden rats and Wandsworth £214 for rats and mice from 1 April 2026. Where the rats come from a neighbour's bins or a landlord's broken drain, though, the notice is the lever that moves them.

Why can't poison just go down in the garden?

Because since 1 January 2025 it has been illegal to use any second-generation anticoagulant rodenticide against an infestation not associated with a building. The Campaign for Responsible Rodenticide Use withdrew open-area use of bromadiolone and difenacoum, with sales ending on 4 July 2024, after residues kept turning up in around 80% of barn owls tested. Since 1 January 2026 professional rodenticides can only be bought on proof of competence, and the actives in shop-bought baits face widespread resistance across central southern England.

In a garden that means baiting is confined to tamper-resistant stations tied to the building, applied to label, and the bulk of the work shifts to trapping, removing the food and closing the route.

What does a professional rat programme involve?

A survey that covers the drains as well as the garden, then treatment, proofing and a follow-up. Westminster's leaflet gives the timeline: most rat infestations take four to eight weeks to control, and multiple-feed baits can take up to ten days to work. Ours runs:

1. Survey the garden, the bin store, the ground floor and the drainage, with a CCTV survey where the runs lead to a chamber.
2. Trap and, where lawful and the label allows, bait in locked stations against the building, with a written note of what is on site.
3. Proof: repair the drain or fit a non-return valve, seal ground-level gaps, mesh the air bricks and close the void under decking or sheds.
4. Return to check activity, collect the stations and confirm the runs have gone cold.

The programme carries a six-month guarantee, subject to survey. Rats are far warier of new objects than mice, so a job abandoned after one visit usually leaves rats avoiding the stations rather than gone.

What to do next

Keep the bins lidded, move the bird feeder and book a free inspection survey so the route is found before anything is quoted. Call 020 3411 2329, Monday to Saturday 8am to 7pm; a same-day visit is often possible. The rat control page explains the programme and the mouse control page covers the smaller droppings, with local pages for the boroughs at the top of the council figures: Camden, Willesden in Brent, Kensington, Hammersmith and Hounslow.