I just put my two week olds into shavings this morning. I love seeing them scratching and burrowing in the shavings. Looks so much more comfortable than the hardware cloth. But they are picking up the shavings and running with them as if they were treasures, and some are pecking at it. I can't tell if they are trying to get the tiny bits on the floor or if they are pecking at the lettering on the newsprint underneath. How would I know if they are still too young to be in the shavings and will cause them problems like blockage?