Edited sentence: After all, if life is common in the universe, why shouldn't it follow typical life patterns.Among the possible catastrophes is predation.If interstellar predation were merely economic and cultural exploitation, aliens might be able to manipulate us provided they had had experience with dozens or hundreds of newbie worlds.Those planetary civilizations which are on the way to step 9 will very likely be liberating nuclear energy in an explosion and/or sending out radio and television waves, hence, will be emitting clear signals of their existence