Cedar chips pose the same health hazard to all animals including humans. The problem is just increased when they are used in an area with less ventilation. Tiny cages and brooders hold in the fumes making small animals and chicks more likely to suffer harm. Larger areas with more air flow will be less likely to have fumes build up but the fumes are still there. If something kills pests and bugs avoid it there is a reason.... It's usually toxic on some level. There are also other things that can impact the toxicity level including how fresh the shavings are. I'd prefer to use a more controlled method that I can measure than spread an unknown amount of toxins around.