**Grey Squirrels** (*Sciurus carolinensis*), typically referring to the **Eastern Grey Squirrel**, are highly familiar, bushy-tailed rodents native to the eastern half of North America. They are successful generalists, thriving equally well in forests, parks, and densely populated urban environments. While ecologically important for dispersing seeds and nuts, they are considered nuisance pests around homes and gardens due to their destructive foraging, tendency to nest in attics, and damage to bird feeders and garden plantings.
Taxonomy and Classification
Grey Squirrels belong to the family Sciuridae (squirrels). They undergo complete life stages (birth, maturity, reproduction). They are diurnal (active during the day) and possess a high degree of cognitive ability, known for their elaborate food caching and retrieval strategies.
Physical Description
The adult Eastern Grey Squirrel is $9$ to $12$ inches long (excluding the tail), weighing $0.75$ to $1.5$ pounds.
- **Coloration:** Predominantly gray fur, often with brownish or reddish tints, and a clean white underside. The large, bushy tail is used for balance, communication, and insulation.
- **Nests (Dreys):** They build nests, called **dreys**, high in tree branches using sticks and leaves, but will readily use tree cavities or human structures (attics, chimneys) for shelter and breeding.
- **Activity:** They are known for their quick, agile movements and propensity to climb nearly any vertical surface.
Distribution and Habitat
The Eastern Grey Squirrel is found throughout the eastern and midwestern United States and southeastern Canada. It has also been introduced to various locations worldwide (e.g., Britain, Italy). Its habitat is deciduous and mixed forests, particularly those with nut-bearing trees (oaks, hickory, walnut). They are exceptionally adapted to urban parks and suburban yards.
Behavior and Conflict
Grey Squirrels are scatter-hoarders, burying thousands of individual nuts and seeds annually, a process vital for forest regeneration (their ecological benefit).
Conflict with humans arises from their destructive habits:
- **Structural Damage:** They gnaw on wood, shingles, and especially electrical wiring and insulation to gain access to or build nests in attics, which presents a fire hazard.
- **Gardening/Property Damage:** They dig holes in lawns, flowerpots, and garden beds to bury or retrieve food, and they consume flower bulbs, buds, and tree bark.
- **Bird Feeders:** They are persistent raiders of bird feeders, often destroying the feeders to access the seed.
Management and Prevention
Control focuses on exclusion and deterrents. Lethal methods are generally discouraged or regulated.
- **Exclusion (Key):** Seal all entry points to the home (vents, gaps in eaves, chimneys) with heavy gauge wire mesh or hardware cloth. Prune branches that hang within $6$–$8$ feet of the roofline.
- **Feeder Deterrents:** Use specialized, squirrel-proof bird feeders, or mix cayenne pepper or capsaicin into bird seed, as mammals dislike the taste while birds are unaffected.
- **Repellents:** Commercial granular or liquid repellents may deter squirrels from digging in flower beds, but effectiveness is often limited and requires frequent reapplication.
- **Live Trapping:** Live traps may be used to capture squirrels, which must then be relocated according to local and state wildlife regulations.
Conservation and Research
Grey Squirrels are managed as adaptable urban wildlife. Research focuses on their cognitive mapping abilities (how they remember buried caches), the dynamics of their disease transmission, and their impact on native European squirrel populations where they have been introduced.