It was while reviewing dozens of Bigfoot cases for my private research group that it became evident to me that, yes, Bigfoot DOES like to operate mostly at nighttime, but the question was why?
I began to review some characteristics like large eyes that appeared to be emanating a glow at nighttime, sensitivity to bright light, and ability to get around easily in the darkness that had me looking to an ancient relative, the Neanderthal.
Upon studying Neanderthal scientists found their eyes were unusually large due to adaptation to high elevation northern areas where light was low. This would create a being with eyes that can see into darkness much more accurately than we ever could and, like the cat and other night creeping creature, the eyes could have a tapedum lucidum like cats. (see this article on Bigfoot eyes by Karl Sup)
The tapetum lucidum, a reflective layer behind the retina, increases the amount of light for night vision in many nocturnal vertebrates. It reflects light outward and thereby allows a second chance for visual pigments to absorb very low-intensity light.