Well, Gabowman, a howler to me is like an ace in the hole. Several reasons to use one, if used correctly. For one, coyotes are territorial, so, if you can convince them that there is a stranger lurking around their place, they often times will come to check out this stranger. With the calling coyotes way of hunting growing, more and more guys/gals are going into the field hunting with distress calls, so, the one that can use a howler has another trick to call those "call shy" educated coyotes. The best time to use it, I believe, varies with location. Some callers use it anytime of day. I use it alot during daylite hours myself. Howling can be productive by itself, especially during mating season. As far as what to do if you howl and you get a howl in response. This can be a whole array of things, but most say to say what the coyote says. I want to stress that they often won't respond, even though they can hear you. I don't think anyone can get them to howl every time, just because they can hear a howl. I often start a stand by doing two or three lone howls, I try to keep my howls in the higher pitch, trying to sound like a young coyote or female coyote. I'll then wait, if no response, about 3-5 minutes, then I will go into my dying rabbit call. One thing about the howl before the rabbit, is this. If you can convince a coyote that there is another coyote in the area, and then convince it that this stranger just caught a rabbit, they will come a running. As far as getting their dander up, using what is called the challenge bark howl, which is a short bark then a short howl, done 2 or 3 times consecutive, I only use this after I have howled, they have howled back, I wait 5 or 10 minutes, they don't show up, so I howl and they howl back, I wait another 5-10 minutes, no one shows, I then will challenge them, especally if I believe I am talking to a male coyote. Learning to use the howler as a tool in the pursuit of coyotes, to me, is the most difficult to master and use effectively. But, when you start talking with them, and convince them that you are who you say you are, and they come, it is the best reward in calling coyotes. Good Luck!!