Ive never had hatchling retics right out of the egg, but for my baby boas I always do live rat pups for their first meal. They usually have enough movements to induce a feeding response but aren't fast enough to spook the baby. If you have access to that I would go with that. Retics have an amazing feeding response and they might even take frozen thawed. Retics are pretty hardy, Im sure they will be eat well.