Ya, we used shredded office paper and Newsprint to raise chicks on, as solid sheets can cause them to slip and splay their legs. I run black walnut alot, and itis toxic to about everything, as is redwood. Aromatic cedar is toxic to mice and gerbals and Guinee pigs. It is used in the animal industry mixed with pine shavings to ward off mites and little creatures that these animals harbor. DONT use it. I understand that oak has an acid that is available when it gets wet, it will harm horse hooves, causing a rot, so I wont use any shavings from my planer for that. We buy alot of bags of white pine shavings as used for horses, it is very fine, and not mulchy. The birds do well with a deep litter concept, about 2 inches thick. There is a claim that the chips get eaten regularly and can affect their digestion. We have had some mysterious deaths, and this may be a part of the cause..and maybe not..