Unless your ball is an extremely undersized hatchling, mouse pinkies are not a substantial enough meal. Rat pinkies aren't even big enough. Most people start their normal sized hatchlings right out of the eggs on mouse hoppers or rat fuzzies. They move up very quickly from there. Get yourself a digital scale and feed your snake 10-15% of its body weight every 5-7 days. Saves a lot of hassle.