For one, he does not love the other snakes company. Ball pythons are not a social animal and live a much happier and healthier life when they live alone. Separate your snakes. There is a small chance of it happening, but they can eat each other. Plus when one gets sick, double your expenses at the vet. It's really not the smartest way in keeping multiple bps.
Two, what is he/she eating and how often? What size is the snake?
Three, can you post pics of your setup?
There is a good chance you just startled him, but I think giving us his eating habits and pics of his setup, we might be able to help you better.