Hey nice going! Don't worry if the new hatchlings only pick at food for a few days. They are still on yoke no doubt. Their appetite will get better each day don't worry! Just keep offering them small amounts of food each day till they grow older. Then you can back off the the food a bit. For hatchling muddies that are slow feeders try live brine shrimp from an aquarium store...believe me they will eat them! Do you know what kind of mud turtles they are?