Of all the reasons a squirrel ends up above a Cambridge ceiling, the simplest is heat, and it explains the timing better than anything else.
The calls do not arrive evenly through the year. They cluster, and they cluster around the point at which nights get cold.
What a roof space is, thermally
A loft sits directly above a heated building and directly below a sealed covering. Warm air rises through the ceiling, insulation slows it rather than stopping it, and the result is a cavity that is consistently several degrees above the outside air and entirely sheltered from wind and rain.
For an animal whose alternative is a ball of twigs wedged in a tree fork forty feet up in an east-of-England October, that is not a marginal improvement. It is a different order of comfort.
Why the calls cluster
The pattern is remarkably consistent. Very little through the summer, when a roof space is hot and there is no reason to be indoors. A steady rise from late August. A peak through October and November as night temperatures fall. Then a long tail through the winter, because nothing about the cold moves them out again.
Grey squirrels do not hibernate. They reduce activity in hard weather and rely on cached food, but they remain awake and mobile all winter. An animal that finds a warm loft in October has every reason to still be there in February, which is how an autumn nuisance becomes a spring problem.
The heating going on is part of the signal. A building that was thermally neutral in August becomes noticeably warm in October, and that change is detectable from the roof surface. It is one reason activity often appears within a fortnight of the heating coming on.
Why better insulation does not help
There is an intuition that a well-insulated loft ought to be less attractive, because less heat is escaping into it. In practice the opposite tends to hold. Deep modern insulation is soft, dry, abundant nesting material, and the space above it is still sheltered, dark and dry.
A great deal of housing around Cambridge has been through one or more insulation upgrades, which means thick loft wool laid over older material. That is excellent for the heating bill and, from a squirrel's point of view, an improvement in the bedding.
What follows from this
- Expect activity to appear in autumn rather than gradually
- Do not expect winter to resolve it — that is the one season it will not
- A property that was found once will be attractive again the following autumn for exactly the same reasons
- The only variable anybody controls is whether the way in is still open
Which is why proofing is treated as a separate piece of work at £180, rather than as an optional extra. Warmth is not something a building can stop offering.
Questions
Will they leave in the spring?
Not reliably. A site that suits them is generally kept, and late winter is a breeding season, so spring is more often when numbers increase.
Does a cold loft help?
Not enough to matter. Even a well-insulated roof space is sheltered, dry and warmer than a tree, which is the comparison being made.
Why does it start so suddenly?
Because the trigger is a temperature threshold rather than a gradual change. Several nights of real cold move a great many animals at once.
Squirrel Control Cambridge
Squirrel control in Cambridge 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.
For squirrel control in Cambridge, call 01502 630 122, or read the Cambridge squirrel control page.