The deer around here all seem to have the same reaction to decoys. They get about 50 yards away and inspect it. If it does not move within a minute or two, or does not respond to their snort/stomp, they are gone!

The only exception may be a doe decoy during the peak of the rut, when the bucks are so horned up they can' t see straight.

I have heard of many putting a real deer tail on their decoy with a piece of fishing line tied to it to make it move. Haven' t tried that yet, but I have heard it works better than nothing.