As the harvest progresses, more and more cover is removed. A certain percentage of deer will basically live in standing corn for months, and once those stalks come down, whitetails will be forced into other bedding habit; usually woods, brush and CRP fields. This typically concentrates deer and puts them into environments where it's easier to hunt them. Also, picked cornfields can become a whitetail feeding mecca, as deer focus on waste grain missed by the combine. Hunting a cornfield in the first week after combining can be truly exciting.