https://youtu.be/II1XNZBEdLQ
Squirrels in times of food shortage, will choice to gnaw on roots or removing the bark of trees looking for food. Maples’ winged samaras and acorns keep squirrels from destroying saplings. Planting a variety of seed producing trees ensures if one “crop” fails; another will provide sustenance for hungry squirrels. Those who want to feed squirrels should stick to peanuts and sunflower seeds. If you really want to feed these rodents do it away from your to discourage them from setting up house in your attic. Scientists have discovered that squirrels, while hibernating, can decrease their heartbeat from 300 to about 10 beats per minute and decrease their body temperatures to zero yet can quickly come out of hibernation. This process is a result of pancreatic enzyme that feeds off fat instead of sugar.
http://www.delta-optimist.com/opinion/blogs/deltabc-1.983313/blog-squirrels-the-true-rodent-1.2143780