Dealing with mice right now? Mouse & Rat Control, by a team that does nothing else.
Rodents move indoors every autumn. The question this year is not whether it happens but when, and the answer looks like being earlier than the calendar would suggest.
What has actually changed
The trigger is not temperature. It is that the fields have stopped feeding them.
Agricultural trade press reported on 24 August 2026 that drought conditions and an early harvest have stripped food, water and cover from farmland at the same time, and that this will displace rats and mice towards buildings sooner than usual. The comment came from the technical and key accounts director at Lodi UK, a rodenticide manufacturer, who put it plainly: vegetation is very dry, crops have come in early, and there is less food and cover available, so rodents go elsewhere.
Two things are worth saying about that source before anyone builds a plan on it. It is one manufacturer's spokesperson speaking to farming press, not independent research, and it is addressed to farmers rather than householders. We are repeating it because the mechanism is sound and checkable, not because it is a study.
The more useful part of what he said is the bit that is not about this August at all: that rodent pressure can no longer be predicted from the normal four seasons, because extreme weather keeps breaking the pattern. In our experience that has been true in West London for several years already. The mild, wet winters that never quite kill a population back, and the dry summers that empty the green corridors early, both push work outside the months it used to sit in.
Why a farmland story matters in a London suburb
It is a fair objection. Uxbridge is not a farmyard.
The mechanism travels, though, because the same thing that makes a field stop feeding rodents makes a green corridor stop feeding them. In our patch that means the Grand Union Canal bank, the golf courses, the allotments, Ruislip Woods and the large mature gardens along the Metro-land streets. When those dry out and the easy food goes, the nearest reliable food and water is a building: a bin store, a compost heap, a bird feeder, a dripping outside tap, a shed with bags in it.
What that changes in practice is timing, not method. The survey you would normally do in October is worth doing in September. Nothing else about it is different.
What opens first, and why it decides the job
This is the part a general autumn article will not tell you, and it is the part that decides whether you are treating a problem or fixing one.
Rodents do not choose a house. They find an opening and follow it. In our experience the openings that get used first, in this housing stock, are these:
- The extension junction. Where a rear extension meets the original back wall there is very often an unsealed gap at the roof line and another where the newer floor slab meets the older wall. Both put a mouse straight into the cavity, and both are invisible from inside.
- The eaves on a 1930s semi. Houses of that age frequently have a continuous open gap along the wall plate. It is not a defect, it is how they were built, and it is a motorway into the loft.
- Service penetrations. Waste pipes, gas entries, cable runs and old aerial holes. The mortar around them is usually the softest thing on the wall.
- The roof line over a flat-roof extension. A slipped tile or an open verge is nothing to a rat, which climbs far better than most people expect.
- Airbricks and suspended floors. A broken airbrick on a Victorian terrace opens the whole underfloor void, and that void is usually shared with next door.
A mouse needs a gap about the width of a biro lid. A young rat needs less than most people would guess. The reason to find the actual route rather than assume one is that a sealed building stays sealed, and a baited building does not.
Mouse pressure and rat pressure are not the same problem
An early displacement year tends to bring both, and they arrive differently.
Mice come in small numbers, quietly, and breed where they land. They will happily live in a wall cavity or under a kitchen unit and never go outside again, which is why a mouse problem often looks like it started indoors. Light, fast scratching high in the wall at night is usually mice.
Rats commute. They will use a building for food or shelter and hold a harbourage outside it, in a drain run, under decking, in a compost heap or along a bank. Heavier, slower movement overhead, and gnawing you can hear from another room, is usually a rat. Because they commute, a rat problem is frequently a drainage problem or a neighbouring-garden problem before it is a building problem.
The reason this matters in a year like this one is that the two respond to displacement on different timescales. Mice show up as soon as the cover goes. Rats often show up a few weeks later, when the harbourage they moved to fails as well.
What to look for now
The signs are the same ones the trade press lists, and they are the right ones: droppings, smear marks, runs and gnawing. What is worth adding is what each one tells you.
- Droppings give you the species and a rough age. Fresh droppings are dark and soft; old ones are grey, dry and crumble.
- Smear marks are grease and dirt left where an animal repeatedly touches a surface. They show you the route, which is more useful than knowing there is a problem.
- Runs are the flattened, cleared paths through insulation, long grass or dust. In a loft they are obvious once you know to look down rather than around.
- Gnawing on a hard edge, a pipe boxing or a door bottom marks where something is trying to get through rather than where it already is.
Finding evidence is the point at which to assess the scale of the problem, not the point at which to buy something.
What changed on rodenticides in 2026, stated properly
You may have seen it reported that from 1 January 2026 farmers need a CRRU-approved certificate to buy and use professional rodenticides. That is close, and it is worth stating precisely, because we checked it with CRRU rather than taking the summary.
The Campaign for Responsible Rodenticide Use, which is appointed by the Health and Safety Executive, confirms that regulation changes taking effect from 1 January 2026 require enhanced proof of competence from everyone buying or using professional rodenticides, not farmers alone. There are two accepted routes, not one certificate:
- proof of training on a CRRU UK approved course completed within the past five years, or
- membership of a CRRU UK recognised Continuing Professional Development scheme.
Evidence has to be produced at the point of sale, and an updated declaration issued in April 2025 must be signed and returned to the place of purchase. The headline change for farms specifically is that farm assurance scheme membership alone no longer counts as proof of competence.
The practical effect for a householder is simple: professional rodenticides are not a shop purchase, and they are not meant to be a first move. Best practice is to start with the least toxic option that will actually work and to match the response to the scale of the infestation.
What we would do about it this month
Nothing dramatic, and nothing that depends on this year being unusual.
Walk the outside of the building and look at the five places listed above. Clear the easy food: bird feed on the ground, an open compost heap, bin bags left out of the bin, fallen fruit. Check that airbricks are intact and that the gap under a shed or decking is not a front door.
If you find droppings, smear marks, runs or gnawing, that is the point to get a survey rather than to start treating. Proofing done before a population establishes is a much smaller job than proofing done afterwards, and in a year where the displacement is arriving early, a few weeks makes a real difference.