The eastern gray squirrel, a familiar sight in parks and backyards across North America, is often perceived as a simple nut-eater. However, the diet of squirrels is far more varied than most people realize, reflecting a highly adaptable survival strategy. These rodents forage for a wide array of foods to meet their caloric needs. This flexibility leads to questions about whether the garden slug finds its way onto a squirrel’s menu.
Are Slugs Part of the Squirrel Diet?
A slug is generally not a preferred or typical meal for a squirrel, and its consumption is likely incidental or extremely rare. While squirrels are classified as omnivores, they tend to reject the terrestrial mollusk for a few practical reasons. The most obvious deterrent is the thick layer of mucus slugs secrete, which makes them unappealing and difficult to consume.
The nutritional return offered by a slug is also relatively low when measured against the effort required to forage for and eat it. Squirrels prioritize calorie-dense foods that offer a better energy payoff for their constant activity. Slugs can also host a variety of parasites, which is a risk most wild animals instinctively avoid.
The rare instances of slug consumption often occur only under duress, such as during periods of extreme hunger or food scarcity. While some animals, including certain species of mice and shrews, eat slugs, the squirrel’s foraging habits rarely intersect with this food source. A squirrel will typically pass up a slug in favor of a more valuable food item.
The Predominantly Herbivorous Nature of Squirrels
The vast majority of a squirrel’s diet, approximately 70 to 80 percent, consists of plant-based material, establishing them as predominantly herbivorous. Their anatomy is adapted for this kind of foraging, featuring strong, chisel-like incisors that continually grow, which are essential for gnawing through hard shells. These powerful teeth allow them to access the calorie-rich inner kernels of nuts like hickory, walnuts, and acorns.
Seeds are another staple, including those from pine cones and sunflowers, which provide concentrated fats necessary for energy reserves. Squirrels consume a wide range of tree products throughout the seasons. They eat tree buds and flowers in the spring, fruits and berries in the summer and fall, and the nutrient-rich cambium layer of tree bark during winter.
Fungi are also a significant part of their menu; squirrels actively forage for mushrooms, which provide nutrients that complement their seed-and-nut diet. Because the squirrel digestive system cannot process cellulose, they rely on foods rich in protein, carbohydrates, and digestible fats. This focus on high-energy plant matter drives their constant foraging and caching behavior, which is central to their survival strategy.
When Squirrels Become Opportunistic Eaters
While plant matter forms the bulk of their intake, squirrels are classified as omnivores, readily consuming animal protein when the opportunity arises. This shift is driven by a need for protein, calcium, and other nutrients not easily found in their standard fare. Pregnant and nursing female squirrels, in particular, require a higher intake of protein to support reproduction and lactation.
During times of food scarcity, such as the late winter and early spring, squirrels actively seek out alternative protein sources. Their omnivorous behavior includes consuming various invertebrates, such as beetles, grubs, and caterpillars. These insects provide a quick and accessible source of animal protein, especially when found incidentally while digging.
Squirrels are known to raid bird nests, consuming both eggs and helpless nestlings to meet their nutritional demands. They will also occasionally prey on small vertebrates, including mice or lizards, or consume carrion if encountered. This opportunistic feeding underscores the squirrel’s adaptability.