Ball Python striking defensively at food?

I got a new BP and instantly had her taken to the vet to see if she had any issues. The vet said she needs to eat right away. I tried feeding her last night. She grabbed ahold of the mouse (frozen thawed) and then let go. I try again today. She keeps missing. I call her vet and ask about it and they gave me the best advice they could over the phone, that it sounded like she was striking at her food defensively. They were going to talk to one of the older vets for advice and call me back, but they never did, and ended up falling asleep and not calling before they closed. So, I was wondering if you guys have ever seen this before. Is it because shes so new and scared? She's never struck at me, only feeding tongs and frozen thawed mice. She's less then a year old, so she's still young. I've never worked with a ball python this young before.

First thing .... stay calm :)
This kind of situation occurs in this very forum nearly every day , I'd say !!

My first thought is to leave him completely along in peace for 7 days and then try this trusted way of feeding a youngster . Vets don't always give THE best advice for snakes in my personal opinion but that's another issue :)

Anyways - 7 days to settle down then :-
This method WORKS if done properly ...
I wait until evening as they're nocturnal of course . I let the rodent thaw out in the reptile room so they get the smell ..
Then I warm up the mouse / rat with a hairdryer and offer with tongs IMMEDIATELY whilst still warm . If refused simply repeat the heating and offering as many times as needed. .
A couple of mine will only strike feed from within their hides so I dangle the warm rodent in front of the hide's entrance - usually works but if it fails simply reheat the rodent with a hairdryer and immediately offer again whilst it's still warm , continue until it's grabbed ...
I always wait until evenings to feed as they're nocturnal of course .

Incidentally , if it shows no interest at all not even a tongue flicker maybe it's best to leave for a week or so !

In the meantime . Check out all the other threads about non feeding snakes in this forum .

Finally . Just let us know your current set up details and then everyone will help you with different things .

Rub or viv and size ?

Ceramic bulb or heat mat underneath ?
Temps warm side and cooler side ?

What kind of thermometer are you using ?
Any hides ?

As much info as possible .

Not sure if it will help or not, but along with what zinc gad said, I had to reheat my little guys food his last feeding. He held it too long after "killing" it. When he went to eat he grabbed it by the butt a couple times then let go. he would push around it flick his tongue at it but not swallow it. I took it out and it had cooled to around 80, same as his ambient temp. I grabbed the hair dryer and heated the mouse back to 95ish and put it back and down it went.

You definitely need to give the guy some time to settle in before you try to feed it. I usually wait at least 5 days -COMPLETELY HANDS OFF- then offer food, then give at least another 2 days for them to digest.

Also, if you haven't double checked, make sure your vet is a reptile vet, preferably with at least some experience with your species in particular. General vets do not know jack all, and even exotics vets who just see snakes on occasion will get things horrifically wrong when it comes to specific species requirements.

There are always exceptions but like the others have said, I'd let the snake get acclimated for a bit. Just make sure your husbandry is spot on and leave it be for a week or so. It's hard but it pays off in the long run. Each time you mess with the snake it just gets more and more stressed and that can lead to bad things.