I've made the same mistake when Crowley was a youngling, I fed him and didn't wash my hands after feeding him, so when I went to take him out of his feeding tub he thought I was dessert, it was so little of a bite though it felt like a mosquito bite. As far as feeding goes, I've always fed my ball python meals the size of the biggest part of his body and fed him every 7 days. Now that he is an adult he gets fed every 10 days, until recently I started ordering from a new company and the rats are slightly smaller so he is back to eating every 7 days.