I woke up this morning to find a regurgitated hopper in my snakes aquarium... this has happend once before but i thought that was because my roommate handled the snake too soon after feeding. I personally fed the snake and transported him back to his main tank. I was very gentle so i am convinced it is not because of rough handling... The tank conditions are normal:
Temperature- ~80 degree average
Humidity- ~65%

What could be causing this? Or is this normal?

Thanks,
-Brant