The moral of trapper trapped is simply to beware for fear to fall into the trap you set for someone else.
The moral of interlopers is that hatred is destructive, as explained by the narrator the story revolves around 2 men that are in the forest because of their mutual hatred that only leads the two of them to suffer themselves.
The similarity lies in how when attempting to sabotage or affect others most of the time the only person you're affecting or whom you are affecting the most is yourself.
Hope this helps :)