So, I found a way to do something funny after you can't think of anything to do. Go to any building with enemies that will never respawn after you killed them(ex. springavile school). Make a pile of frag mines. then drag all the body in the buildings to the spot where you made the mine pile. Make sure you loot everything from their body. Then make a doggypile with the bodies and watch the meat shower when you detonate the mines!