The squirrel digestive system also plays an important role in the survival of truffles. While above-ground mushrooms can spread their spores through the air, truffles grow below ground.

But unlike the squirrels you may see chowing down on ... After properly preparing acorns, they're usually pretty gentle on the digestive system, Best says. "They contain a significant amount ...

Sunflower seeds also lack a number of vitamins that squirrels need. Anything containing onions or garlic can irritate their digestive system. Chocolate contains thobromine, which can kill a squirrel.