Squirrels

Additional Information

Grey Squirrels in the UK: A Widespread Pest

The grey squirrel (Sciurus carolinensis) was deliberately introduced to the UK in the 19th century, originally from North America. Since then, it has spread throughout most of mainland England and Wales, thriving in a variety of environments. Although primarily found in broadleaved and mixed woodlands, grey squirrels have successfully adapted to urban and suburban settings. They are a common sight in parks, gardens, and even residential areas, where they can sometimes become a nuisance.

Why Are Grey Squirrels a Problem?

While many people enjoy watching grey squirrels in their gardens, they can cause significant damage when they invade homes and buildings. One of the most common issues is their tendency to enter roof spaces in search of shelter, particularly in the colder months. Once inside, squirrels can be highly destructive:

• Chewing on woodwork – Grey squirrels have strong, sharp teeth that continuously grow. To keep their teeth in check, they gnaw on various materials, including wooden beams and rafters in loft spaces. Over time, this can lead to structural damage.
• Stripping insulation from electrical wiring and pipes – This poses a serious fire hazard. Exposed electrical wiring increases the risk of short circuits and fires, while damaged water pipes can lead to leaks and costly repairs.
• Tearing up fibreglass insulation – Squirrels often use insulation materials for nesting, which can reduce the energy efficiency of a home and lead to higher heating costs.
• Drowning in water tanks – Occasionally, squirrels become trapped inside water tanks, leading to contamination and potential health risks.

The Impact on Native Wildlife

Beyond their impact on buildings, grey squirrels have also had a detrimental effect on native wildlife, particularly the native red squirrel (Sciurus vulgaris). Grey squirrels outcompete red squirrels for food and habitat, and they also carry squirrelpox, a virus that is deadly to red squirrels but harmless to greys. As a result, red squirrel populations have declined significantly in areas where greys have become dominant.

Preventing and Managing Grey Squirrel Infestations

If you suspect a grey squirrel infestation in your home, it is crucial to act quickly. Professional pest control services can help remove squirrels safely and advise on prevention methods, such as sealing entry points and trimming tree branches near buildings.

Remedy:

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DO SQUIRRELS CARRY DISEASES?

Squirrels can carry the squirrel pox virus, which is responsible for the disease known as squirrel pox. This disease presents in red squirrels with symptoms resembling mange, scabs, or myxomatosis, leading to rapid weight loss and, ultimately, death.

Symptoms

The disease may cause behavioural changes in infected animals, particularly towards the end of their illness. They become lethargic, more approachable, and tend to consume large volumes of water. The virus is commonly found within the UK grey squirrel population, but its effects on this species remain unclear. Squirrel pox spreads through body fluids and shared parasites, making it especially important to keep red and grey squirrels apart.

Grey squirrels that carry pox antibodies typically do not show any visible symptoms. The pox-type virus is quite resilient and can survive outside the host for extended periods, especially in dry weather, where it may remain viable for over a month. Wet conditions significantly reduce the virus’s viability.

The virus can be killed by good hygiene practices using anti-viral veterinary disinfectants. Once in a squirrel population, the virus spreads rapidly, and isolated woodlands can see a complete loss of red squirrels.

The Northern Ireland Squirrel Forum has developed a Standard Operating Procedure (SOP) document detailing best practices for cleaning and disinfecting traps and squirrel feeders.

SNISF Standard Operating Procedure – Trap and Feeder Hygiene

It’s important to note that there is no known risk to humans from squirrel pox, but washing your hands after handling any animal is recommended, as other pathogens may potentially cause harm.

Other Diseases

Red squirrels are particularly vulnerable to a range of diseases, likely due to their isolated populations and limited genetic diversity. If an infection enters an isolated population, it can cause a significant reduction in numbers, with insufficient new squirrels from other populations to replenish the loss.

Squirrel feeding sites can increase the risk of disease transmission, as close contact between animals is more likely. Disinfection of feeders, as detailed above, can help prevent the spread of disease.

Recent research indicates that squirrels may carry a strain of Mycobacterium lepromatosis, which causes leprosy (Henson’s Disease) in humans. Although it is unclear whether squirrels can transmit the bacteria to humans, leprosy is primarily spread through respiratory droplets from coughs and sneezes. It may also spread via ingestion or entry through cuts and bites. However, over 95% of humans exposed to the leprosy agent do not develop symptoms.

Be aware of the symptoms of leprosy, which may take several years to manifest, and seek medical attention if they occur. It’s important to inform your GP of any work with squirrels.

Symptoms of leprosy in humans can affect the skin, nerves, and mucous membranes.

Additionally, a recent study by the University of Glasgow found that grey squirrels carry the Borrelia bacteria, which can cause Lyme disease in humans when transferred via ticks. Lyme disease is a serious illness that can affect the joints, heart, and nervous system.