To floor, or not to floor?

[Happytat]

I am about to begin building my first chicken tractor. During the planning process of the elevated coop, i started thinking about how i would clean it. My mind jumped to pull out boards first, then, I thought, why have a flooor under the roosts at all? The tractor would be in the feild (NOT the yard), so dung would not be stepped in; and the coop will be in the run, so predators could not get in. I just thought i would ask if this would pose any problems to the chickens' health.Thanks!

 

[willowbranchfarm]

It wood be colder since its on the ground. And predators could still get in.