One of my budgies has a bit on the quiet side for the past few days. He's lively and plays with the toys, eats, cleans his feathers, hangs upside-down, etc. but I think he started quieting down when I started making him step up onto my finger. I've been training him and trying to get him out of the cage for awhile and he's been doing really well! I didn't notice that he was going quiet until today, actually... He sometimes makes little chirps when he wants one of the other birds to preen him and he also comes close to the edge of the cage when he wants to chew on my hair but he's been so silent. I'm not all that worried but it's good to get a second opinion.