It all depends on the situation. My situation for example: Before season starts I have to cover a large area with limited cameras. To cover the property well, I like to cover every 100 acres. I use a 50 lb bag of corn on the ground every time because it takes them awhile to get use to a feeder. I have found that it takes the majority of the deer in the area I place my camera a day or two to find the corn to start coming to it regularly. Then 7 days of good activity until I don't get anymore new deer coming to the bait, but just in case I leave it out a couple more days. So, for me 10 days then I move to a new location. And usually the corn is gone by this time as well.