if you can keep them at the proper temp for their age and draft and predator free it would be ok. Dont put them directly on concrete put a wood or styrafome barrier between the concrete and the brooder
If you are trying to exclude predators like mink and other weasels from your run 1/2" hardwarecloth is necessary because they can climb and can get through any opening that is larger.
In the fall just before the 1st frost I cut back my hosta plants to the ground and feed the leaves to the chickens. These plants have never had any toxic chemicals near them.
I also have a fish pond and when I am cleaning it out in the fall I take all the water hyacinths and water lettuce that...
So far I have caught 4 adult mice and 4 juvinal mice. Since the trap won't harm my chickens I leave it set in the run to collect any more invading mice.:D
Great build. Chheck out my thread http://www.backyardchickens.com/t/1085105/gadget-for-those-of-you-building-coops-runs-this-spring-time-saver-hand-saver. Neat little gadget for cutting hardware cloth and saving you hands. I also cut polycarbonate roof panels with it.
Recently my DH left the run door open while he was cleaning the coop. 2 nights later while looking at my chicken cam in my.run I noticed 2 mice running around eating my chicken food. I needed a way to safely trap the mice. I found directions for making a 5 gal bucket mouse trap on you tube...
Eating feathers sounds like she is lacking in protein. Give them some dried meal worms and some black oil sunflower seed as treats. Both are high in protein.
Don't wait longer that 3 days to put the chicks under the broody hen. They need to imprint on the hen or she might not accept them. Good luck I have raised almost all my chicks under a broody. :yiipchick