I have the opposite problem! The instant it's light out (they define "light out" as "15 minutes before official sunrise time") they are READY. As soon as they spot me shuffling across the yard, they start clucking with great excitement.
Their hatch door is hinged at the bottom, with a wire attached so that I can let it down gently (without slamming). The instant I unlock the door, even if I'm holding the wire, half the time they will knock the door right out of my hands! They practically kick it down, shouldering each other aside, let me out out out OUT OUT OUT!!!!
Then once they're all out in the fenced part of the tractor, they're all like, "Oh, huh, this isn't as exciting as I thought." Like it's a real let-down.