TAKE A LEAD
I always have the dog on a lead when I introduce it to a pen. Initially I walk it around until I can see a rabbit tucked up in a patch of rough grass. I tend not to have too many stick piles in my pen because in the early stages I want the dog to see the rabbit flush, as I have found that this is the easiest way to begin the game-scent connection. Once I have found a rabbit and it flushes, I immediately blow the sit/stop whistle. I want the dog to sit up; standing is unacceptable. I am not concerned with where the rabbit has gone, I concentrate on the dog. You may find that the first flush does not get much of a reaction but this will change on subsequent finds.