I was re-re-repairing the fence yesterday and I threw the doors wide open, took their food and water out of the coop, laid down a trail of mealworms, scratch, food, and (only used in emergency situations) Fruit Loops. The dumb birds stood at the edge of the coop, ate everything they could reach with their necks stretched aaaaaaalll the way out and that was it. They went a full 8 hours without food or water; without leaving the coop.
This isn't my first experience with chickens so I'm well aware of the fact that they are not in the Animal Kingdom's Gifted & Talented class but, seriously, I have the dumbest 5 chickens on the planet! They can't figure out how to use the ramp, I built multi-level platforms and roosting poles in the coop for them and the only time they've been on those platforms or poles is when I put them there - they immediately freak out and get the hell off. I have *ground* chickens. They've no desire to roost, they all sleep in a pile in the corner. The one chicken I was teaching to use the ramp in and out the chicken-sized coop door (the 'smart' one and not Alpha but the leader) just stood on the ramp, facing the open door, let out a giant "BWAA-KAAK" and flew up and into the solid wall above the opening. Repeatedly.
*sigh*
I miss my duck. She was smart.