Identifying Signs of a Squirrel Infestation
Noises from the loft around dawn, disturbed insulation, and openings near the roofline can all point towards a squirrel infestation. Understanding these warning signs can help property owners recognise what may be happening, assess potential damage, and know when professional help may be needed.
Grey squirrels are a frequent cause of unexplained sounds in lofts across UK properties, particularly those close to woodland, parks, and gardens containing mature trees. Several indicators can reveal their presence, ranging from distinctive noises within roof spaces to visible signs of damage and nesting activity. Being able to compare these signs with those associated with rats or mice can also help property owners determine what may be causing unusual activity.
Noise is often the first indication that squirrels have gained access to a building. Their movement across timber and ceiling structures can create noticeable sounds, especially during the early morning and late afternoon. By the time these noises become sufficiently obvious for a property owner to investigate, however, squirrels may have already been occupying the loft for several weeks. They can cause damage to insulation, electrical cables, and other building materials during this period. Looking for additional evidence during a roof inspection or when entering the loft for another reason can help reveal an infestation at an earlier stage and potentially limit repair costs.
Recognising Squirrel Noises in a Loft
Squirrels can create several distinctive sounds when moving around inside a roof void. One of the clearest is the sound of rapid movement across ceiling joists. Their footsteps are heavier than those of mice and can produce a noticeable series of thuds as they move quickly across the timber. This activity is usually more apparent during their main periods of activity, around two to three hours after sunrise, often between 6am and 9am, and again approximately two to three hours before sunset.
Repeated chewing can also be an indication of squirrel activity. When squirrels gnaw on hard materials, the sound can be persistent and rhythmic. Their chewing is generally deeper and more forceful than that of mice. Mice are commonly associated with intermittent nocturnal gnawing, whereas grey squirrels are predominantly active during daylight. Scratching that repeatedly comes from the same area may also suggest activity, particularly when it occurs close to an entry point or where a drey is being constructed.
Grey squirrels can occasionally make vocal sounds that may be heard inside a property. Their alarm calls can sound sharp and repetitive, with a bark-like quality. These calls are more commonly heard outdoors, although they can sometimes carry into a building when squirrels are involved in territorial behaviour around the roofline. A lone squirrel may be relatively quiet compared with a female caring for young, as a breeding female is likely to make frequent journeys between the nesting area and outdoor feeding locations.
Because grey squirrels are mainly active during daylight, noises that continue primarily throughout the night are more likely to be associated with rats or mice. Squirrel movement is typically heavier than the quick sounds made by mice and has a more energetic, bounding quality than the slower movements often associated with rats. The timing of the noise can therefore provide a useful initial indication of the animal responsible.
Evidence You May Find Inside the Loft
Grey squirrel droppings are normally cylindrical with slightly tapered ends and generally measure around 8 to 12 millimetres in length and 4 to 5 millimetres in diameter. When fresh, they are usually medium to dark brown, becoming lighter and more crumbly as they age. Their size and shape can make them difficult to distinguish from rat droppings. Squirrel droppings, however, are typically lighter in colour and have a less strong smell. Mouse droppings are considerably smaller, usually measuring between 3 and 5 millimetres, and tend to have more pointed ends.
A squirrel drey within a loft can provide another clear indication of activity. These nests may appear as large, roughly rounded collections of torn insulation, such as glass fibre or mineral wool that has been pulled apart into loose strands. Squirrels can also use bark, leaves, paper, cardboard, fabric, and other soft materials found in the loft. Dreys are often positioned in corners or alongside walls and can measure approximately 20 to 60 centimetres across. A nest occupied by a breeding female and her young may be larger and more tightly packed.
A grey squirrel drey in a loft space can destroy an area of glass fibre insulation equivalent to several square metres within a single breeding season, as the animal gathers and compacts material for the nest.— British Pest Control Association (BPCA) Technical Guidance, 2021
Squirrel Gnawing and Signs Around Entry Points
Grey squirrel gnaw marks are usually larger and deeper than those left by mice. They can also have a rougher, chiselled appearance compared with the finer marks commonly associated with rats. Within loft spaces, squirrels may gnaw timber roof components, particularly around areas where electrical cables are present. Damage to PVC sheathing around electrical cables is especially concerning. Squirrels may also chew insulation around plastic water pipes and other hard materials as they work to maintain the length of their continuously growing incisors.
Outside the property, signs of access can include fresh gnawing on timber fascia boards or soffits around the roofline. Roof tiles may become cracked or displaced, leaving openings that are large enough for squirrels to use. Compressed dirt, fur, or other traces around the edges of gaps can indicate that an opening is being used repeatedly. Scratches may also appear on paintwork or render beneath an access point. Regularly used entry holes can become darker and visibly worn around the edges because of repeated contact with the squirrel’s body and the accumulation of natural oils.
Signs of Squirrels Around the Garden and Outside
Outdoor evidence can often appear alongside signs of squirrel activity within a property. Trees may show areas of bark removed in a spiral pattern around the trunk or branches, particularly species with smoother bark such as beech and sycamore. Other possible indicators include small, shallow holes in lawns or flower beds where squirrels have buried or recovered nuts, damaged bird feeders, and squirrels repeatedly travelling across roofs or disappearing beneath the eaves.
Seeing squirrels regularly running along rooflines or gutters may indicate that they are searching for or using an opening in the roof structure. If a squirrel disappears beneath the eaves and does not emerge again straight away, this may suggest that it has discovered a usable access route into the property. This is more significant than a squirrel simply travelling across the roof, as it could indicate that the animal is entering and using the loft space.
Identifying the Species and Arranging a Professional Inspection
A combination of daytime loft noises, a sizeable drey, cylindrical droppings measuring around 8 to 12 millimetres, and visible evidence of external access can strongly point towards grey squirrel activity rather than rats or mice. However, it is possible for more than one pest species to occupy the same roof void. Properties with several access points can sometimes have both grey squirrels and rats present, and neither species may be immediately apparent without a thorough inspection.
Professional pest controllers across Sheffield and South Yorkshire can conduct detailed loft inspections to establish which species are present, find potential entry points, assess any damage, and recommend a suitable control programme. Obtaining a professional assessment at an early stage can allow control measures to begin before a small squirrel problem develops into an established breeding population. Acting sooner can help reduce the overall cost of treatment and limit the amount of repair work needed once the infestation has been dealt with.
Frequently Asked Questions
What do grey squirrels sound like in a loft?
Grey squirrels in a loft produce a heavy, rapid bounding movement across ceiling joists — a characteristic thud-thud pattern that is heavier than mice and faster than rats. Activity is concentrated at dawn and late afternoon. Persistent daytime gnawing on timber or cables is also common. If loft noise occurs primarily at night, rats or mice are more likely than squirrels, which are diurnal animals.
What do grey squirrel droppings look like?
Grey squirrel droppings are cylindrical, slightly tapered at both ends, 8 to 12 millimetres long, and 4 to 5 millimetres in diameter. Fresh droppings are medium to dark brown; dried droppings become lighter and more crumbly. They are similar in size to rat droppings but typically lighter in colour and less pungent. Mouse droppings are much smaller (3–5mm) with more sharply pointed ends.
How do I tell if squirrels or rats are in my loft?
The key differences are timing and movement patterns. Squirrels are active during daylight hours — noise from squirrels is concentrated around dawn and late afternoon. Rats are primarily nocturnal, with most activity after dark. Squirrel movement is fast and bounding; rat movement tends to be slower and more cautious. Squirrel droppings are lighter in colour than rat droppings and have less odour. A pest controller can confirm the species from inspection.
What does a squirrel nest look like in a loft?
A grey squirrel drey in a loft is a substantial, roughly spherical pile of torn loft insulation, bark strips, leaves, and soft materials collected from storage. It is typically 20 to 60 centimetres in diameter and is positioned in a corner or against a wall. A breeding drey used by a nursing female will be larger and more densely packed. It is much larger than a mouse’s nest and more structured than a rat’s nest.
What are the signs of squirrels getting into a roof?
External signs of roof entry include: fresh gnaw marks on timber fascia or soffit boards at the roofline; gaps under displaced or broken roof tiles; dark worn patches at gap edges where the squirrel has repeatedly passed through; and squirrels observed running along the roofline and disappearing under the eaves. Internally, a combination of loft noise, droppings, nesting material, and cable or insulation damage confirms entry.
What damage do squirrels cause to electrical cables?
Grey squirrels gnaw on PVC electrical cable insulation — not because they eat it, but because gnawing is a constant biological need driven by continuously growing incisor teeth. Gnawing strips the insulation from cables, exposing the live conductor underneath. Damaged cables in a loft space represent a genuine fire risk. Any electrical cables running through a loft space with confirmed squirrel activity should be assessed by a qualified electrician before the space is re-insulated.
How quickly should I act if I suspect squirrels in my loft?
Act as soon as you suspect activity. Grey squirrels breed twice a year, and a single pair that gains access in late summer can establish a breeding colony by the following spring. Early action — professional inspection, trapping, and proofing — costs significantly less than resolving a multi-animal infestation with an established drey and extensive cable or insulation damage.
Contact a pest controller for a survey when you first notice the signs rather than waiting to confirm the problem with certainty.
Apex Pest Control Ltd 