Not every Rhino can communicate with Rocks. Rocks give off vibrations, which is how they make their thoughts available. Not every Rhino has the patience to get the message.
RhinoRockReaders say that Rocks are most interested in their own mass; are they getting bigger or smaller, working their way to pebbleness or bolderhood? We are told that Rocks do not care which direction is their trend, but they do ponder.
One thing with Rocks, they are seldom in a hurry.