When out locateing at nite the coyotes are not going to answer you every time. I usually have my best luck when the sky is clear and no moon and very little wind.. I also found out my hearing is'nt the greastest so i take my 10 year old son along when out locateing and he can hear them over 3/4 of a mile away. Once located then i move around and get closer so i can hear them and then I can tell how many there are and if there are any young ones in the bunch..
Howling is a usefull tool but it can also ruin youre stands. dureing the summer and early fall the pups will tend to shy away from howling. Most are still trying to establish there own territorie or maybe still with mom and pop and they are'nt looking to get there butts kicked yet..
The howling will work to get in the older coyotes but animal distress sounds would be best to use if you are after the yoy and then you may also get an adult to respond also...
I like to use rabbit distress on my stands first and as a last resort go to a howl.. but if i'm targeting older coyotes then i use just coyote vocals and this is done later in the year...T/[beeep]
