I have 2wk old RIR. It is beautiful outside so we are going to let them out in the grass in their coop tractor. I am not sure what bugs they will find and eat. should i give them grit? My store only had some funky blue medicated grit. I am guessig that is for adults cuz it had oyster shells, calcium and other things. I did by chick scratch which i know they can not have w/o grit and that it is a special treat not food. my kids have a sand box will that sand work for chick grit? should i give them some before going outside and giving them some scratch or can i just give them scratch and sand at the same time?