Common Pests – Squirrels

Lifecycle and Habits

The North American Grey Squirrel was introduced into Britain between 1876 and 1929. It is mainly a resident of woodland, where it has replaced the native Red Squirrel. It is now commonly found in parks and gardens.

Squirrels have two breeding seasons every year; the first litters are normally born in late February and March. Squirrels have a second litter between June and July. The average litter size is 3 or 4.

The nest is normally built in the fork of a tree at a height of 2-15 meters from the ground. It is common for them to also nest in roof- spaces of houses. The nest itself is built from twigs and leaves, lined with grass, moss and animal fur, or if built in a roof space often formed from insulation material.

What Squirrels Eat

Although the squirrel is omnivorous, the diet is mainly vegetarian, eating the seeds of most broad- leaved and coniferous trees. When available birds eggs, young nestlings, grain, fungi, buds and young shoots and inner bark layers on trees are also eaten.

Problems Linked to Squirrels

The most common damage caused by grey squirrels is the gnawing of tree bark, which occurs mainly during the months of May, June and July. Squirrels will also cause damage by robbing birds nests, taking fruit in gardens, digging holes in lawns and uprooting bulbs. Although less common, a major problem can occur when they gain access into attics and roof-spaces and cause damage to electrical wiring and insulating material.

Preventing or dealing with an infestation

Squirrels most commonly gain access to roof- spaces by way of overhanging branches from trees and/or a missing or displaced roofing slate or tile. Overhanging branches should be cut back to a reasonable length from the building. Missing roofing slates or tiles should be replaced, but first make sure that the squirrels are out of the roof-space first.

There are three main ways of controlling squirrels in an urban area – spring trapping, cage trapping and poisoning with Warfarin.

Professional help

It may be advisable to contact a reputable Pest Control company, either for advice, or to carry out a professional treatment. The British Pest Control Association has a list of its member companies on its website, for all areas.