I also have the siren but never use it. When Bill (who owns Wildlife Tech calls) was here hunting with me, we used it some and had them howl back but I think the howling calls on the caller work much better. I locate all the time as well as look for lots of track in the snow when calling. Coyote droppings are fine to but when calling an area, I generally go out at night and howl in several locations. The next day I hunt the area. I almost always get coyotes in the areas where I howled. I am a firm believer that howling will produce you coyotes if you hunt those areas in the next couple of days after.