Depends on how smart you want the preys to be.
I mean, you could make a basic system where if the player enters a specific zone around them (collision with an invisible rectangle representing the prey's sight or reaching coordinates depending on one or more variables...), they start going the opposite direction. You wouldn't even need pathfinding.
If you need them to navigate around walls, however, then pathfinding would be the way to go : you could set a bunch of checkpoints for preys, have them look for the farthest one that isn't in the threat's general direction relative to themselves, and have them run for it until the predator's been shaken off.
Does that help at all? Sorry if I've wasted your time!