Winter can be a difficult time for deer, especially when looking for nourishment. This one got desperate, perhaps?
We really have no way of knowing the struggle this deer was having due to the winter, and can’t speculate the reasoning behind what it did.
What we do know is that a guy shot a squirrel out his window, then filmed this deer taking some bites.
Do you think that deer actually chewed and swallowed, or was it merely munching on something it was curious about?
Whatever the case, the idea that deer are strictly herbivores may need to be reconsidered.