Your not the only one my 4 chins chatter in there sleep so does my bird @_@ it's weird but I'm guessing they dream about food cause I have one that I find sleeping under the food dish and I think my other boy dreams about taking a dust bath cause he rolls around in his sleep to as he chatters !
I think it be cool to be a chinchilla for a day to see what its like being one and see what they are thinking or dreaming about lol !
