I just finished my new coop and run around the middle of April. I had some left-over pine shavings that I was using for litter material at first. My girls are a little over two months old. I have recently (about a month ago) purchased a paper shredder. I thought it would be an inexpensive way to litter the 4'x4' roost coop. I have been using the Sunday paper, which I believe is printed with soy ink. I dont want to put my girls in any danger and wondered if this material was safe to use