When I first saw this device hanging on the side of the house, I thought it was a crossbow that might be used for taget practice. It turns out you put a little food on the tip of the wire arrow and pull it back to cock it. Then you watch and wait. When a mouse comes up to smell the food . . . you pull the release. I explained we like to use traps that have springs so that you don't actually have to be there to catch the mouse. She told me her way was much more fun.