It really depends on what you call an old deer. Deer will becoming in "hiddening" after they turn 4+years because of the three year olds become the dominate bucks and just want to fight. Pressure plays a lot on if a deer becomes naturnal as well. But in a perfect world as the deer ages he becomes dominate and will cruise around whenever he wants... as he ages to 4+ years the younger deer want to kick his ass and he becomes less and less active..... Deer during the cold months will sleep about 80% of the day. During the summer months they will sleep 50% of the day eating whenever possible to prepare for the rut.