IMPORTANT !!! Choose the right size of the trap carefully - larger trap is intended for rat sized animals and smaller trap is intended for mouse sized animals Don't use larger trap for mouse sized animals because of the mouse is not strong enough and has not enough weight to activate the trap. It will probably eat the bait without activating the trap.Don't use smaller trap for rat sized animals because of the rat is too big for the smaller trap to kill it. If the rat is not injured when activating the trap, it can return and eat the bait from deactivated trap. Tips & Tricks: The trap is still set and bait is gone > Try to use a solid type of bait and tie up this bait using threads to pedal. There are two small holes for this purpose. Then mouse must put much more effort to acquire the bait and trap will be activated.The trap was tripped and bait is gone > It seems that the trap was too sensitive and the trap was premature activated. In this case we recommend use lower sensitivity. See attached manual. If you also use a solid type of bait tied to pedal then you will increase the chances to trap mouse.Cought mouse escaped with the trap > In order to prevent this use holes in platform of trap for nailing or screwing to the base. Choose the right trap CLASSIC METAL MOUSE TRAP fully galvanized fully burnished CLASSIC METAL RAT TRAP brass coated fully burnished fully galvanized EASY USE MOUSE TRAP Super Sensitive (multicolored)User Friendly (all gray) - slightly less sensitive, but very easy set ONE CLICK MOUSE TRAP metal snap trap designed especially for mice and other smaller animals with unique adjustable trigger sensitivity