Today I switched over my chicks 1 of which is 4 days old the rest are about 6 days old. I had them on newspaper until today and switched them to pine shavings is this o.k? They seem to be picking at it and eating a little here and there. Should I be concerned about them swallowing it? Can it digest o.k? Thank you for your help, I love my babies and want them to be healthy and happy.