I have 25 10-day old barred rock and Ameracauna chicks, and just transferred them from paper towels to shavings. All were growing well and eating well from the feeder. Now that I've switched them, about 2/3 seem to be attacking the food in the feeder, but the other 1/3 seems to be eating the litter. Is this just because it's new? Should I be worrying? They've been on the new litter about 1/2 hour, and they all seem psyched about it--scratching and flapping around like crazy. There are just those few.....