I have 4 pullets, about 10 weeks old. I let them free range for about 3-4 hours a day. When it's time to go back to the chicken run, 3 of them will go, one will not. I've tried treats, letting the others back out to help her along, but no luck. It's almost like she just doesn't get it. She will walk right past the door trying to find a way in. Any advice to make this less stressful for me and the bird? The chicken run is pretty large 10ft x 4 ft, the coop is 5ft x 5 ft, so they have ample room to move around.