When I go to feed I always scatter some pellets on the ground before I fill the feeder and the waterer. That way they don't have to wait on me. Lately I've notice my little bantam cochin roo making this noise. I call it the chicken purr, but it's not a purr like a cat. It's more like a low, constant repeating of a soft "bock" if that makes sense. It's a contented little sound and he does it for a few minutes when he first begins eating off the ground. He does this even if he's just eaten an hour before and you bring something else. Anybody else ever had a chicken "purr"? He's the only one of mine who do this. After he's eaten his fill though, he goes into the crowing fits. That's another story altogether... But it's cute.