They most certainly need to be set where the quarry will walk in or walk away at an angle where they are in the trigger window longer, verses walking by cross ways. Not to scare anyone but i just received my fourth moultree 200 after sending the first three back after developing failer with them. But when they are working, im completly satisfied with em, other than the pics where it looks like light bulbs screwed into there heads at night. [8D]