It seems that they've become less effective with each year. Where I hunt, your better off leaving them at home after the first month and a half or so of the season is over. Using a remote seems to help a lot. By just turning them on at certain times, maybe after seeing a flock off in the distance and flipping it on until the get a little closer seems to be more effective, almost treating it like you do flagging for goose hunting. It seems that later in the season, less is more.