I've learned to refrain from setting out a decoy when it's absoultely still -- i.e. -no breeze whatsoever. The absence of movement from a turkey decoy seems to make the animals suspicious.

I had 5 deer standing around mine stomping and trying to get it to move. When it didn't, they got spooky and left. About 45 minutes or so later, I called in two longbeards which started to strut when they saw the decoy, but then stopped when it never moved at all. This decoy had been responsible for the death of numerous birds --including two 20lbers last year from the same set-up, so it ain't a bad decoy.

Mine stays in my vest if it's too still.