"They feed for a little while after sundown and a liitle while before sun up."
Right there is why it would be easier. Plus, they do feed off and on all night, although those are the highest activity times.
It is amazing what you can see at night. Your eyes take a little while to fully adjust, but animals aren't afraid to the degree they are in the day. Deer will let you walk right up to them before they spook. I've had a lot more deer take off snorting from 15yds and scaring the hell out of me at night. In daytime, they usually hide or sneak out long before you get there.
Think about it, it's a lot easier to get a camtracker picture of a buck than it is to actually shoot one. Why? Because they move more, they hit the food sources, they're not afraid.
BM, you really think deer are smart? Even the smartest animals like dogs, chimps, dolphins, ect, aren't what I'd call smart. If you can teach them to sit or jump through a hoop, it's an accomplishment, and I doubt you could teach many ungulates those tricks, aside from a pig. You wouldn't see so many deer hit by cars if they had any sense. Deer are dumb as a rock, they just have extraordinary senses, and instincts. They don't avoid you because they think there may be a hunter in those trees, they avoid you because they instinctually move into the wind, if possible, and they can smell you from 1/4 a mile off. Big bucks survive by being cautious and not walking around in broad daylight, not by problem solving.