I have just thought of this and now it's bugging me; What do Reapers do when they are not attacking/reaping.

Sure you could say that they hibernate but there has to be moments when they have returned yet are not under attack or themselves attacking.

Do they talk to each other about....... Reaper stuff, I mean the Reaper on Rannoch says "Harbinger Speaks of you" so they must talk, but is that all they do, gossip about Shepard?