You dont, you just do the best you can to keep up with it
Kaan will go in the same place, most of the time. Sometimes he forgets and sometimes he just cant be bothered to fly up there. If he's sitting on me sometimes he'll give a little squeal and I know he's going to poop on me and have to shoo him up there.
Funny to see him fly up there, go poop, then look down at it and say 'BIG POO!'