Fun fact : You can make predator eat other predator in two random pred mode. I manage to make Bella eat Satie in nightmare mode since pred have a bigger capacity. I'm pretty sure Ligeska (snake) can eat any pred since she has the most capacity of the four. And yes, they can digest other preds, though they escape easily once eaten. I manage to make Ligeska digest Satie and she burped a bone that was almost triple the size of a student bone.
Viewing post in Escape From Deep Pit University comments
You just have to quickly hide behind another predator once one as noticed you, the same way you force a pred to swallow a student. Just be careful, because you have to be quick enough so that one pred see you and the other pred that you are trying to get swallowed dont have time to grab you. The easiest way I found was at the start of a "two random pred" game, run straight to the cafeteria (where both preds spawn). They always spawn facing the kitchen and there is often one pred behind the other. So go in front of the pred that is the furthest from the kitchen until they notice you, then quickly hide in front of the second pred, since you need the second pred to be between you and the first pred. Don't be to fast though, because the second pred might swallow you first.