What Do Squirrels Eat? Wild Diet, Safe Foods & Dangers

Anyone who’s watched a squirrel wrestle an acorn into a hole knows these rodents take their meals seriously. But what’s actually on the menu—and what’s secretly dangerous—might surprise you. This guide breaks down what squirrels eat in the wild, which human foods can harm them, and how to coexist with them without causing harm.

Primary Foods: Nuts, seeds, fruit · Other Items: Fungi, grains, vegetables · Occasional Protein: Insects, eggs · Natural Sources: Trees, woodland · Supplements: Roots, bulbs, bark

The following table summarizes the core dietary patterns and safety considerations based on documented squirrel research.

What do squirrels eat in the wild?

In the wild, tree squirrels are opportunistic foragers with a strong preference for high-fat foods. Gray squirrels in hardwood forests rely heavily on oak, hickory, elm, and maple trees for their caloric needs.

Nuts and seeds

Nuts form the backbone of most squirrel diets. According to Mass.gov (state wildlife authority), nuts such as oak acorns, hickory nuts, beechnuts, and walnuts may comprise up to three quarters of a gray squirrel’s annual diet. Red squirrels focus more narrowly on conifer seeds, fungi, buds, and inner bark.

Fruits and vegetables

Squirrels raid gardens and farm fields for fruits, vegetables, seeds, and grains. Beyond nuts, they eat wild fruits, berries, leaf buds, and even tree bark when necessary. A Critter Control wildlife report notes they also consume bird eggs and scavenge where opportunity allows.

Fungi and grains

Fungi play a significant role, particularly for red squirrels. Research from the NCBI PMC database documented European ground squirrels eating grasses like Cynodon and Carex–Cyperus (each making up more than 20% of their diet). Under scarcity conditions, these squirrels even adapted to consume the toxic Solanum elaeagnifolium—demonstrating remarkable dietary flexibility.

The implication: squirrels aren’t picky, but their choices have consequences. Foods with poor calcium-to-phosphorus ratios (Ca:P) like peanuts (1:6) can cause metabolic bone disease if eaten frequently, while acorns (1:2) are safer in moderation.

What foods are poisonous to squirrels?

Many foods that seem harmless to humans are actually toxic to squirrels. Exotic Nutrition (wildlife nutrition specialists) maintains a detailed database of hazardous foods that every feeder should know.

Common toxic human foods

Avocado contains persin, a fungicidal toxin harmful to rodents—even the pit and skin pose danger. Onions damage red blood cells in squirrels. Chocolate is perhaps the most well-known poison: theobromine causes heart problems, seizures, or death, according to Dallas Wildlife Tips (wildlife experts).

Salty foods like chips, pretzels, and salted nuts lead to dehydration and salt toxicity. Dairy products are harmful because squirrels are lactose intolerant, resulting in stomach upset. Processed sugary foods (candy, bread, cookies) contribute to obesity and metabolic bone disease.

Garden plants to avoid

Moldy or spoiled foods carry toxins that cause seizures or death. If you’re growing a garden, be aware that squirrels may sample plants that are toxic to them. The Edward Noble food safety guide (rodent nutrition resource) provides Ca:P ratios showing that corn (1:50) is extremely unhealthy for squirrels—far worse than peanuts (1:6) or even acorns (1:2).

The pattern: even healthy-seeming foods can be harmful based on their nutritional profile, not just toxicity. Watch for signs of distress if a squirrel has eaten something unusual.

Should I feed the squirrels in my garden?

This is where many well-meaning people go wrong. The U.S. Fish and Wildlife Service (federal wildlife agency) explicitly warns that feeding wild animals—whether intentional or accidental—can harm their health and human safety.

Pros and cons of feeding

What this means: the risks of habituation and nutritional imbalance typically outweigh the benefits of supplemental feeding in most suburban settings.

Safe feeding alternatives

If you choose to feed squirrels, Exotic Nutrition recommends unsalted raw nuts like pecans and walnuts in moderation. Squirrels also enjoy apples, berries, carrots, and leafy greens from gardens—but limit sugary fruits. Insects like dried mealworms provide necessary protein.

The pattern: woodland areas naturally provide the food squirrels need. If your property borders wild spaces, maintaining natural cover and food sources is preferable to direct feeding. Invest in a squirrel-proof feeder if you want to provide supplemental nutrition without creating dependency.

Do squirrels remember humans?

Squirrels have surprisingly good memories. Research and observation by Wildlife Online shows squirrels remember cached food locations for weeks or months. But what about remembering humans?

Evidence from observations

Wildlife experts note that squirrels remember people who feed them. They associate specific humans with food rewards and will approach those individuals repeatedly. Grey squirrels use deceptive caching to protect food supplies—they may fake burying a nut if they sense they’re being watched, according to Ark Wildlife (UK wildlife specialists).

Implications for feeding

This memory capability cuts both ways. Squirrels that receive food from humans may become bold or aggressive in seeking more. Ground squirrels forage primarily during early morning or late afternoon to avoid heat, but feeding schedules can shift their natural patterns. The UCANR (university agricultural extension) observes that California ground squirrels change their diet based on seasonal availability—human feeding can disrupt these natural adaptations.

What to watch: if a squirrel approaches you without hesitation, it may have been fed by humans before. This isn’t necessarily friendly behavior—it can indicate habituation that puts both the animal and people at risk.

What smell do squirrels hate the most?

Deterring squirrels without harming them often comes down to smell. Squirrels have keen olfactory senses and will avoid foods or areas that smell unpleasant to them.

Top deterrent scents

The most effective natural deterrents include spicy compounds (capsaicin from chili peppers), strong aromatic herbs (peppermint, lavender, eucalyptus), predator urines (fox or coyote), and citrus peels. Mothballs (naphthalene) are effective but controversial due to toxicity concerns.

How to apply them

For garden protection, place cotton balls soaked in essential oils around planting areas. Sprinkle capsicum-based powders near vulnerable plants. Commercial predator urine products are available from wildlife control suppliers. Reapply after rain since effectiveness decreases when scents dissipate.

The trade-off: smell deterrents require consistent reapplication and may need rotation as squirrels adapt. Combine multiple deterrent methods for best results rather than relying on scent alone.

How to support squirrels safely

Supporting squirrels doesn’t necessarily mean direct feeding. Creating habitat that naturally supports their dietary needs is often more beneficial.

• Plant native oak, hickory, and maple trees that produce nuts
• Allow fallen fruits and berries to remain in your yard
• Leave dead trees (snags) that host fungi and insects squirrels eat
• Provide water sources during dry periods
• Avoid pesticides that reduce insect populations squirrels rely on for protein

For those who still want to offer supplemental food: focus on items with appropriate Ca:P ratios. Acorns, while technically containing tannins, are generally safe in moderation. Avoid peanuts entirely given their 1:6 ratio and mold contamination risk. Corn should never be offered given its extremely poor 1:50 calcium-to-phosphorus balance.