so i open my email and i have this long email about how this person's ball python has an eating problem. Here is the email...

I was wondering if I could ask you a question. We have a young female ball python that just won't eat...and we are getting worried. We have tried all sorts of frozen mice different sizes/colors, and wouldn't touch them, and lastly tried a live mouse. She killed it right away, started to eat it, got it half down, past the front legs, then and spit it out. We are not experts and would love your advice. Thanks for any help you could give.

so it prefers live mice but i'm not sure as to why it would spit it out unless they disturbed it or it was sick. suggestions?