Squirrel or Rat in the Loft? How Cambourne Homeowners Can Tell the Difference

Damage is the most reliable evidence in a roof space, more so than droppings, because the two animals behave differently enough that the results look different.

What a Squirrel Does

BPCA's list for grey squirrels in roof spaces is specific: gnawing on woodwork and ceilings, stripping insulation from electrical wires, tearing up fibreglass insulation, and contaminating cold water tanks and the attic space with urine and droppings.

• Insulation torn into long strands and gathered into a mass. This is nest building and it is unmistakable — not compacted or flattened, but pulled apart and moved
• Coarse gnawing on rafters, joists and boarding, in substantial patches rather than small marks
• Damage at the roofline from outside — a gnawed soffit, fascia, barge board or eaves opening, obvious from the ground
• Stripped cable, in lengths
• Stored items opened and dragged about, boxes, suitcases, furnishings
• Contamination of an open water tank

What a Rat Does

• Gnawing on cable, plastic and lead pipe, and timber — BPCA note rats have to gnaw to keep their teeth in shape and are not shy about what
• Insulation disturbed on a route rather than torn apart and gathered — a channel through it rather than a nest built from it
• Greasy smear marks along joists, at gaps, and where anything passes through
• Droppings grouped along a route
• Evidence lower down in the building, because a rat has climbed through the structure to get up there
• No damage at the roofline, usually — rats enter low and climb inside

And Then Look Outside

This is the confirmation. A squirrel has to get in at roof level, and the opening is coarse, visible and usually accompanied by pale exposed timber, chewed plastic or a lifted tile. Stand back in the garden with binoculars or a zoomed phone camera and look along the whole roofline.

A rat that has reached a loft has almost always come up through the building from ground level, so there will usually be something to find downstairs — and nothing at all to see on the roof.

Both Damage Cable, and Both Matter

Whichever it is, stripped insulation on a conductor in a roof void is a fire risk and it is out of sight. If there has been activity in a loft with wiring in it, it is worth having an electrician look, and it is worth not leaving the animal there while you decide.