This is the single most important question to settle before any work starts, because the answer changes the method, the entry points and the whole shape of the job.
Fortunately it is usually settled from the sofa, without anybody going into the loft at all.
The decisive one: time of day
Grey squirrels are diurnal. Rats and mice are nocturnal. That single fact resolves the majority of cases on its own.
- Noise from first light, and again late afternoon, quiet overnight — squirrel
- Noise starting as the house goes quiet in the evening and continuing into the small hours — rat or mouse
- Noise only in spring, only at the eaves, with chirping — birds
Weight and rhythm
- Squirrel. Heavy. Thumps, rolling, short bursts of running that stop abruptly. Loud enough that people assume something much larger
- Rat. Lighter but continuous — scurrying, with a scrabbling quality, often along the same route repeatedly
- Mouse. Very light and quick, frequently scratching in one place for long stretches
- Bird. Light, fluttering, confined to the eaves or a chimney flue
Droppings
- Squirrel. Raisin-sized, barrel-shaped with rounded ends, scattered
- Rat. Larger, tapered, laid along defined runs and in corners
- Mouse. Rice-grain sized, very numerous
- Bat. Mouse-sized but crumbling to glittering insect fragments — protected species, work stops and specialist advice is needed
Where they came in, which is the biggest practical difference
Squirrels arrive from above and enter at roof level: eaves, verge, soffit, a roof-to-wall junction. Rats usually arrive from below — drains, gaps at ground level, airbricks, underfloor voids — and travel up inside the structure through cavity walls and service runs.
This is why the answer matters. Proof a roof edge against a rat that is coming up a cavity wall from a defective drain and you have spent money on the wrong end of the building. The species determines where the work happens, not just how.
Other tells
- Gnawing. Squirrel gnawing is coarse and heavy; rodent gnawing is finer and more nibbled
- Smell. A persistent musty, ammonia-like smell is more typical of an established rodent population than of squirrels
- Nesting material. Squirrels build a bulky ball of shredded material; rats build flatter, more compressed nests
- Sightings. Anything using the roof, gutter or a fence line in daylight is worth watching for a minute
- Grease marks. Dark smears along a run at low level suggest rats
If you are still not sure
Note the times for three days and photograph anything you can see from the hatch and from the ground outside. That is normally enough to settle it over the phone, and it is a great deal safer than climbing about to find out.
Questions
Could it be both?
It happens, particularly in older properties where the roof space and the wall cavities connect. The timing pattern usually shows it — noise at both ends of the day and overnight.
Does it matter if it is a mouse instead?
Yes. The work, the entry points and the cost are all different, which is why the identification comes first.
Are grey squirrels and rats related?
Both are rodents, which is why both gnaw continuously. Their behaviour, routes and habits are otherwise very different.
Squirrel Control Costs
Squirrel control is £280 fixed cost. Proofing work, where it is needed afterwards, is £180. Call 01502 630 122 and tell us what you have heard or seen.
To arrange squirrel control, call 01502 630 122, or read the squirrel control page.