We need a little more info to help you.
Can you describe your set up and husbandry? Enclosure, temperatures and humidity. And are both snakes housed separately?
How much do the snakes weigh and what size prey are you feeding? How often do you offer food? How long ago did you have mites? Mites can be stressful and the snakes went off feed from that stress possibly.
Ball Pythons tend to be finicky eaters anyway though. I have some garbage disposals that eat every time, but I also have one that will only eat every few weeks and another that will only take a specific size prey. Balls can go up to a year without eating as well without losing much weight. It just depends if the snake is naturally off feed or husbandry related. Snakes tend to loose weight rapidly if its a husbandry or other error.
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