User blog comment:AdmiralPedro1stFleet/FANS PLEASE READ. Drew Karpyshyn's ORIGINALLY INTENDED ENDING/@comment-1440333-20130525133723/@comment-72.49.149.251-20130525185107

And you could indirectly program the buggers in a hunter-killer role to search for A.I. related constructs and devour their "brains". Plus, the nanites could embed themselves into the Reapers and their children and act as little signal-receivers for Sheperds "Dominatus Broadcast" (sorry, personal name for it) Feel free to punch holes kin the idea if you so desire, this is just the explanation I've been using since 2012.