Chocolate is bad for squirrels. It contains theobromine, a compound that squirrels (and most small mammals) process very slowly, allowing it to build up to toxic levels. Even a small amount of dark chocolate can cause serious harm to a squirrel weighing only 400 to 700 grams. If you’ve been feeding squirrels in your yard or at a park, chocolate should be completely off the menu.
Why Theobromine Is Dangerous
Theobromine is a naturally occurring stimulant found in cacao beans. Humans break it down efficiently, but small mammals lack the same metabolic speed. In squirrels, theobromine lingers in the body and overstimulates the heart and nervous system. The effects can include vomiting, diarrhea, rapid heart rate, seizures, and in severe cases, death. Because squirrels have such small body mass, the threshold for a toxic dose is far lower than it would be for a dog or a cat.
Dark Chocolate Is the Most Dangerous
Not all chocolate carries the same risk, but none of it is safe. Dark chocolate contains roughly 883 mg of theobromine per 100 grams. Milk chocolate contains about 125 mg per 100 grams, making it less concentrated but still harmful to an animal that weighs less than a pound. White chocolate contains virtually no theobromine (below detectable levels in lab testing), so it poses minimal risk from that specific compound.
That said, white and milk chocolate are still loaded with sugar, fat, and dairy, all of which cause their own problems for squirrels. The theobromine ranking matters most in terms of acute poisoning risk: dark chocolate is by far the most dangerous, followed by milk chocolate, with white chocolate at the bottom.
Sugar and Dairy Cause Problems Too
Even setting theobromine aside, chocolate is a poor food for squirrels. Most mammals in the wild produce very little lactase, the enzyme needed to digest lactose (milk sugar). Squirrels fall into this category. When they consume dairy-containing foods like milk chocolate, the undigested lactose ferments in the small intestine, producing gas buildup and diarrhea. For a small animal, diarrhea alone can lead to dangerous dehydration.
Refined sugar is another issue. Squirrels in the wild eat foods with naturally low sugar content. A diet that includes candy, chocolate, or other processed sweets can lead to obesity, dental problems, and nutritional imbalances. Sugar provides calories without the calcium, vitamins, and protein squirrels need to maintain bone density and healthy teeth. Over time, sugary foods can cause metabolic bone disease, a common and painful condition in captive and urban squirrels fed inappropriate diets.
Urban Squirrels Already Eat Too Much Junk
Squirrels in cities and on college campuses regularly eat human food waste, and the pattern gets worse in winter when natural food is scarce. A study of gray squirrels foraging in trash bins found that over 76% of the food items they pulled from garbage were starchy, processed foods like french fries, bread, pizza, and chips. Less than 3% was fruit. Squirrels were most likely to dig through bins during the coldest months, when stored nuts and natural forage run low.
Researchers also observed squirrels tearing open plastic bags and foam packaging to reach food, then licking plastic wrappers. This means urban squirrels aren’t just eating nutritionally poor food; they’re also at risk of ingesting plastic and other hazardous materials. Offering chocolate or other processed snacks adds to this problem by reinforcing the habit of seeking out human food instead of foraging naturally.
What to Feed Squirrels Instead
If you enjoy feeding squirrels, there are plenty of options that match what their bodies actually need. The best choices are foods that provide calcium, healthy fats, and fiber without excess sugar or salt.
- Nuts and seeds: Acorns, whole roasted pumpkin seeds, and almonds are the best options, ideally still in the shell. Hazelnuts, walnuts, pecans, and pistachios are also fine. Limit nuts to about two per day per squirrel, since they’re calorie-dense. Keeping the shell on gives squirrels something to gnaw, which helps keep their continuously growing teeth worn down.
- High-calcium vegetables: Kale, broccoli, dandelion greens, arugula, bok choy, butternut squash, and watercress are all excellent. These provide the calcium squirrels need to avoid bone disease.
- Fruits (in moderation): Blueberries, strawberries, apple slices, grapes, and watermelon work well as occasional treats. Fruit is higher in sugar than vegetables, so keep portions small.
- Wild foods: Pine cones, magnolia cones, dandelion greens, rose hips, and nontoxic tree branches are all natural favorites that squirrels would eat without human help.
Avoid feeding squirrels corn, peanuts in large quantities, sunflower seeds as a staple, or anything salted, flavored, or processed. These are common offerings that fill squirrels up without providing adequate nutrition. The goal is to supplement their natural diet, not replace it with something that leaves them malnourished despite having a full stomach.