Gnaw marks are usually treated as damage to be counted. They are also a record of where an animal has been spending its time, and read that way they are one of the most informative things in a roof space.
Why the marks map the behaviour
Gnawing is incisor maintenance, done wherever the animal happens to be resting or pausing. So a concentration of marks is a place where it spends time, and a scatter of light marks is a place it passes through. Unlike droppings, the marks stay exactly where they were made and cannot be displaced.
Reading the concentrations
- Heavy work in one small area — a resting site. Usually near a nest, and generally the part of the roof the noise comes from
- Heavy work at a roof-edge detail — the entry point. This is purposeful enlargement rather than incisor wear, and it is normally the single largest concentration on a property
- Light marks along a joist — a travel route. Follow it: one end leads to the nest, the other towards the way in
- Marks on cable — opportunistic, wherever the cable crosses a route. Also the one that matters
- Marks around stored items — investigation, and often material being taken for nesting
Two concentrations in different parts of the roof usually means two things. Either a nest and a separate entry, which is normal — or two separate entries, which changes the proofing job.
Reading the age
Fresh gnawing is pale and sharp-edged against weathered or dusty timber, with loose chips nearby. Old gnawing has greyed over, its edges have softened and dust has settled into it. Both together — old marks with fresh work on top — means a site used before and used again, which is worth knowing because it points at an opening that has been there for years.
Reading the height
Marks at joist level are travel and resting. Marks high on a rafter or at the ridge are less common and usually mean a nest up in the apex, which is warm, dry and as far from disturbance as a roof space gets. Marks low down at the eaves are almost always the entry.
How to record it
From the hatch, with the torch held away from the camera so the beam rakes across the surface. Raking light shows the grooves; light from beside the lens flattens them into nothing. Put a coin in the frame for scale — incisor width is what separates squirrel marks from rodent ones — and note which direction from the hatch each photograph is looking.
From the hatch, not from inside. Mildenhall has a good deal of housing with unboarded lofts where deep insulation hides the joists. Everything worth photographing is visible from the opening.
What to do with the map
Match it against the two other pieces of evidence: which room the noise is above, and which elevation looks wrong from outside. When all three agree, the job is largely diagnosed before anybody arrives. When they disagree, that is itself worth reporting — in an extended or terraced property it usually means connected roof spaces.
Questions
How do I tell squirrel marks from rat marks?
Width and pattern. Squirrel grooves are broader, and the damage is scooped and splintered rather than a neat hole. Photograph with a coin for scale.
Marks but no noise. What does that mean?
Check whether they are fresh or weathered. Old marks with no current noise means a past episode — and an opening that is probably still there.
Is it worth photographing all of it?
The concentrations and anything on cable. A general shot in each direction gives the context.
Squirrel Control Mildenhall
Squirrel control in Mildenhall 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 Mildenhall, call 01502 630 122, or read the Mildenhall squirrel control page.