I'm not sure, if they've just hatched recently they can live off their yolk sacs for a few days to a week. You could try giving them some aquatic insects or baby pond snails and chopped up earthworms. Another thing you could also try is to feed them something smelly to stimulate their appetite. Put in a few pieces of canned tuna or some cut up frozen shrimp or fish fillets. That has always worked for me. If you can't get them to eat by the end of the week it might be a good idea to release them because baby musk turtles can be very stubborn and are not always the easiest species to get to eat.