I have no problems with predators at night, I use a red heat lamp and I guess the nail holes in the bldg. deter their efforts. Little red eyes. Only thing is they liked to burned the barn down from being knocked down. So it must be secured. I had to give them warm honey and water for a week or so from the smoke inhalation. Had a few burned, the weaker ones were killed by the others. The mice and rats, well lets just say the roosters are on their game and the hens eat them whole. I also have 25 small bantams that I free range too! They are my smarter chickens. Very flighty though. And they love grits and black sunflower seeds, grapes, and bananas. They killed my collards this year so keep them far away from those. I hang collards by strings in the winter and plant winter rye in their pastures. Also, the mites, lice, and termites I use a powder in their nest, around the floors, where they dust bathe. I use ashes from burnt wood and trash and Diatomaceous earth.
