Grey squirrels (Sciurus carolinensis) are a familiar sight in many parts of the UK. Introduced from North America in the late 19th/early 20th century, they're now widespread in woodland, suburban gardens, parks—and often cause issues for native red squirrels and trees.
Where They Live
Habitat
Grey squirrels favour deciduous and mixed woodlands. They also thrive in suburbs and urban areas where there are mature trees, gardens with feeders, and enough canopy for movement.
Nests (Dreys)
They build spherical nests (dreys) made from leaves, twigs, moss etc., often in tree forks or large branches. They may also use hollow tree trunks. Females sometimes maintain more than one drey in their home area, allowing flexibility if threatened or disturbed.
Range
Their home range varies. Typically a few hectares (2–10 ha) for many individuals; males especially may roam wider during mating season.
When They're Most Active
Understanding when grey squirrels are most active is important both for observing behaviour and for management/trapping.
Daily Pattern (Diurnal/Crepuscular Tendencies)
Grey squirrels are diurnal—they are active during daylight hours. But within the daylight period, their activity often peaks in the early morning and late afternoon/dusk.
Seasonal Changes
In spring & summer, there tends to be more continuous activity during the day, though still with stronger activity in the cooler and safer parts of daylight (morning & late afternoon).
In autumn, as natural food (nuts, seeds, fruit) becomes plentiful, they spend time both foraging and caching (burying food). Activity remains strong.
In winter, activity diminishes somewhat. Because daylight hours are shorter and temperatures lower, squirrels are less active especially during midday. They still forage, but rely more on stored/cached food. Sometimes activity is concentrated in fewer and more predictable time windows (morning, late afternoon) when conditions are tolerable.
No True Hibernation
Grey squirrels do not hibernate. Unlike some mammals, they remain active throughout the year, though their activity rates drop in the coldest weather or when food is scarce.
Why Their Activity Varies: Drivers & Behaviour
Food availability: When nuts, seeds, and other natural food sources are abundant (autumn especially), they have less incentive to range widely. But in lean times, they forage more, travel farther, and may take greater risks.
Temperature & daylight: Cold or very hot conditions reduce activity. Squirrels avoid extreme cold; shorter daylight means less time to safely and efficiently gather food.
Predation risk & safety: They prefer canopy movement over travelling on the ground, when possible. In areas where risk is higher (predators, human disturbance), they may adjust times or use safer routes.
Breeding seasons: There are peaks of activity around breeding—when mating, rearing young, gathering food for growing young, etc.
Hibernation? Not for Grey Squirrels
A key point: grey squirrels do not hibernate. Although they may appear less active in winter, they continue to forage (often using stored food), move about, maintain their dreys, and generally go about their surviving business.
Managing Grey Squirrel Populations with Humane Traps: The Goodnature A18
Because grey squirrels are invasive in the UK and can damage woodlands, gardens, bird populations, and threaten red squirrels (via competition, habitat destruction, spread of squirrel pox), humane control methods are used in many places. One such device is the Goodnature A18 Grey Squirrel trap.
Here's how it works, its advantages, and best practice:
What the Goodnature A18 Trap Does
Humane & automatic: The A18 is a tree-mounted, CO₂-powered, self-resetting trap designed to humanely dispatch grey squirrels. It is non-toxic (no poison). The dispatch is intended to be instantaneous.
Trigger & lure: The squirrel enters a narrow tunnel (≈ 5.4 cm entrance) to reach bait/lure at the back. When it triggers the device, the strike is delivered. The lure basket lets you use different baits (nuts, seeds, etc.).
Digital counter & reset: A counter registers the number of dispatches ("strikes"). The trap resets itself automatically a number of times (e.g. up to 18 squirrels per CO₂ canister in some versions) before needing maintenance/gas refill.
Best Practices for Using the A18 Efficiently & Ethically
Placement: Mount on mature trees where grey squirrels are known to travel. The base of trees that have nearby canopy connections are good. Avoid dense undergrowth right around the trap; squirrels prefer clearer areas for easier access. Use a trap guard to protect against chewing or damage.
Bait & lure: Use strong-attracting food sources that the squirrels are accustomed to (e.g. nuts, sunflower seeds, "grey squirrel lure"). Refresh bait regularly. Seasonal changes can affect what they prefer.
Timing: Because squirrels are more active in certain times of the day and certain seasons, aligning trap deployment with those peaks increases effectiveness. For instance, late winter through early summer (approx. Feb–July) tends to be the most effective window for trapping when squirrels are more active, breeding, foraging, etc.
Non-target/ethical considerations: Use guard and ensure the trap entrance size minimises accidental catches of non-target species. In areas where red squirrels or other sensitive wildlife are present, consider live traps or alternative methods so that non-targets can be released.
Why It Matters & How You Can Use This Knowledge
Understanding grey squirrel behaviour—when and where they are active, what drives their movement, and when they are weaker—can help:
- Gardeners identify when damage (e.g. bark stripping, raiding nests, eating seeds) is most likely
- Conservationists or woodland owners optimise timing of population control to be most humane and effective
- People considering traps like the Goodnature A18 can deploy them more strategically, achieving better results and fewer unintended negative impacts
Summary: Key Takeaways
| Topic | Key Point |
|---|---|
| Activity Rhythm | Grey squirrels are active during daylight hours, with peaks in early morning & late afternoon; less active midday, especially in winter |
| Seasons | Spring through autumn = high activity; winter = reduced, but still no hibernation |
| Habitat | Woodlands, |