You are definitely not going to call in any more predators just because you have a decoy out. Like the others mentioned, it's basically a distractor. I try to use one if I have kids on a set or I have someone that is new to calling coyotes. In both of these situations, I know there is going to be some excess movement and we might need more time than normal to get a shot off. In most cases, the decoy will buy you that extra time and help distract the approaching predator. It does take a little extra time to set it out and go pick it up but it's a good trade off. Also, you definitely want your sound source coming from the decoy. This is where having a remote with your e-caller will come in handy.