Calling moose is almost a crap shoot. Sometimes they come on the run. You can hear them coming from a long way crashing bush, grunting like crazy. Other times it' s just a few quite grunts as the bull slowly moves towards the caller. Sometimes you don' t even hear a thing and are about to stand up to go somewhere else...and holy crap he was right behind you. For such big animals they can be silent in the woods.
The weather can often play a huge role. If it' s too warm, it can suck. A little bit of frost and look out, you could have some fast action.
That' s why I love hunting moose. It can be completely unpredictable. There is nothing like a bull moose coming to the call!