Urban Grey Squirrels

The grey squirrel (Sciurus carolinensis) is an introduced species which is now common throughout most of England. Squirrels are often viewed as an attractive addition to our wildlife and they regularly frequent gardens. However, they may become a nuisance and, where they gain access to buildings, the chewing of materials, including electrical wiring, can cause damage and pose a fire hazard. They also strip bark from trees, which causes serious economic damage in woodlands. Competition for food and habitats with the native red squirrel (Sciurus vulgaris) has contributed to the decline of the red squirrel.

Where control measures are justified, the most appropriate approach will normally be to use traps. However, poison baiting may be the most cost-effective measure for protecting woodland.

Advice on preventing damage in woodlands should be sought from the Forestry Commission.

Biology & Behaviour

Grey squirrels are found in a wide range of situations, from urban parks and gardens to rural woodland. They spend part of their time foraging on the ground but are always within easy reach of trees.

Urban Grey Squirrel

Foods eaten include acorns, beech mast, nuts, fruits and bulbs. They will also sometimes take birds’ eggs and nestlings. Their habit of bark stripping is probably a combination of social behaviour and feeding activity and occurs mainly between April and July.

Grey squirrels usually have their young either in dreys (nests made of twigs and leaves) or in holes in trees. They will also breed in roof spaces where they may build their nests from loft insulation or other available materials. Grey squirrels do not hibernate but are less active during periods of cold weather.

They normally have two litters each year; the first in February to March and a second in June to July. The litter size averages three to four, and the young are independent at about three months of age. The grey squirrel’s main food supplies of acorns and beech mast vary in abundance from year to year and this has an important influence on breeding success and survival.

The choice of control technique will depend on the situation and the type of damage. Control can either be carried out by private individuals, other occupiers or a pest control contractor. The Environmental Health Department of the Local Authority may also offer a service but this is usually chargeable.

Problems in buildings

These occur mainly where squirrels gain access to roof spaces. In these situations, they may cause damage to electrical wiring, insulation or other materials, and the noise they make can create a nuisance. In such cases the aim should be to capture the grey squirrels in the roof space and then humanely despatch them. The access points should be proofed to prevent further invasions. Whenever possible, control should be undertaken outside the breeding season.

Cage trapping and proofing are the methods normally recommended for use in roof spaces.

Cage trapping

Single catch, live capture cages are most suitable for this purpose and are available from a number of sources, including agricultural merchants and game suppliers.
Squirrels do not like moving in open spaces, so traps should be placed near brickwork, joists, or other available objects and structures. The use of traps around the outside of buildings can also be effective.
Securing the trap door in the open position and baiting in and around the cage for several days before setting, can improve trapping success. Use whole yellow maize, peanuts, wheat or a mixture of these. Good results are more likely to be achieved when natural food sources are in short supply. Avoid stocking bird tables during trapping operations.
Once set, traps should be inspected at least once a day. Captured squirrels should be removed outdoors and then humanely dispatched. They can be run into a sack and killed by a sharp blow to the head. Alternatively, they may be shot whilst in the cage, using a suitable weapon. Shooting should only be undertaken by an experienced, competent person. Care must be taken to avoid the risk of ricochet and traps should be placed on soft ground to reduce this hazard. Trapped squirrels should not be drowned as this is considered to be inhumane.
Captured grey squirrels must not be released or allowed to escape into the wild; it is illegal to do so.

Spring trapping

Only approved spring traps can be used, and these are designed to kill the target animal humanely. Currently approved traps include the Fenn Mk 4 and 6, the Springer Mk 4 and 6, the Magnum and the Kania 2000.
These should be set in a natural or artificial tunnel. The latter can be constructed from timber or other suitable materials and the entrances of all tunnels should be restricted to reduce risks to non-target species. Children and pets can be particularly vulnerable and the use of such traps in domestic situations is not normally recommended.
In roof spaces, gaps between joists or other suitable areas can be used, adding materials as necessary to create a tunnel.
The tunnel helps to ensure that the squirrel is caught correctly. Care must be taken to ensure that the arms of the trap can operate freely. Bait such as whole yellow maize, peanuts, wheat or a mixture of these can be used to attract the animals to enter the tunnel.
Spring traps should be inspected at least once a day, and carcasses removed and disposed of discretely, either by burning, burying or via refuse collections when they should be securely wrapped.

Proofing

Having dealt with squirrels that have gained access to buildings, action should be taken to prevent others from entering vulnerable areas.

Crushed wire netting, metal sheeting or other suitable materials can be used to block any entry points. It is important that all access routes are identified but no action taken until it can be confirmed that no squirrels remain within the site to be protected. Baffles attached to rainwater down pipes or cables and wires may assist in reducing access to roof spaces.

However, the climbing abilities and ingenuity of squirrels should not be underestimated.

The removal of tree branches, which are in close proximity to walls and roofs, will eliminate potential access routes.

Avoiding the spillage and availability of bird or pet foods will assist in reducing attraction to squirrels. The use of squirrel-proof bird feeders may help in this respect.

Poison baiting

This technique is not normally recommended for use within buildings or garden situations. It can be difficult to persuade squirrels to take bait when other food is available, and the animals may die within the building, leading to problems with smell and insect infestations. Particularly in outdoor locations, there is also a risk of non-target species gaining access to bait points.

The rodenticide formulation approved for use against grey squirrels can only be used in domestic premises by a Local Authority or professional operator, and this product cannot be purchased by householders.

There are restrictions and conditions placed on the use of poison baiting in certain counties and the product must not be used where Pine Martens or Red Squirrels are present. Advice on this aspect should be sought from the Forestry Commission.

Legal aspects

It is illegal under the Wildlife and Countryside Act 1981 to use any bow or crossbow, any explosive other than ammunition for a firearm or a live decoy.

Squirrels are protected from ill-treatment by the Wild Mammals (Protection) Act 1996.

Under the Wildlife and Countryside Act 1981 it is illegal to release grey squirrels or to allow them to escape into the wild.

Only spring traps approved for use against squirrels under the Spring Traps Approval Order 1995 may be used.

Squirrel Information Leaflet

The following leaflet is presented in Adobe Acrobat (.pdf) format. You may find it useful to read our Help before downloading information.

Squirrel Information Leaflet (.pdf 126KB)

Contact Information

For further information on squirrels and pest control, please contact Environmental Protection

This page last updated: 24/02/2005

Environment and Planning

See Also:

Urban Grey Squirrels