My chickens have been roosting on a 2 "1/2" wide board about 2 ft. above the floor of their coop since they were little, but lately I noticed they are always looking up, trying to find a higher spot when it's time to roost. We just installed nestboxes for them and also raised the roost - now I'm concerned that it may be too high. It's 39" high - about a ft higher than the highest nesting box. They did all manage to get up there, but I was reading that larger breeds can get hurt if their roost is too high. If they do get bumped off during the night, will they be able to get back up in the dark? Our chickens are EE's, barred rocks, barnevelders, production red, & leghorns (all 16 weeks old). Do I need to lower their bar or add a second lower bar as a step or is 39" a safe height for the breeds I have?