User blog comment:DeadDATA/Cerberus In ME3: How They've Grown/@comment-24990641-20110819114443/@comment-1900300-20110823070655

Maybe they consider us to great a threat and have given up reproducing using us. Or they intend to do so after ensuring no threat will interfere. After all there is probably trilions of us in the galaxy. Not that hard to find a few million.