are you sure they were maggots and not intestinal worms? like roundworms? were they long and stringy or short and plump? If its maggots then flies must have laid eggs on the poo and they hatched. This happened to me over the summer when we were gone for a couple days. Make sure you clean the poo if it piles up under the roost every morning, this will definitely help with the flies. And dust alittle DE or seven dust on the shavings in the coop. It will also help keep some of the bugs down. If it was intestinal parasites in the poo you probably need to deworm everyone. As for it being red, every once in a while they shed their intestinal lining and it shows up in the poo. I would definitely check for parasites though bc this can also cause it to be red. Okay, I think I have said poo enough lol. Hope this helps!