I have 2,5 weeks chicks. So far I've used towels for bedding, but it does get a little messy and I want to get them accustomed to shavings before moving them outside. I've twice tried to change to pine shavings but remove them when I see the chicks start eating them. Can they still die from eating pine shavings at 2,5 weeks? When would it be safe? They aren't just investigating them, but eating the smaller pieces of the shavings, and they don't stop at one or two.