Move forward six months. Nibbles no longer squeaks in that high pitched way. Her feet are up like Callie's and she paws the bars just like Callie. Their cage is in the dining room and there are times I'll be eating dinner and feel that prickle that someone is watching me. I'll look up and there are Nibbles and Callie, staring at me through the cage quietly but intensely.
Note they both can squeal. But now I only hear when they are not pleased about being picked up out of their cage.
So basically Nibbles now behaves like Callie does when she wants treats. It made me curious about how often this happens.
Over the time I've had them, they all have started mimicking each other. Mr Bubbles still doesn't wheak, but he bites the wires on his cage for treats and attention now. Scruffy wheaks now whenever he hears Sammy doing it. The only thing my herd lacks is the ability of all 4 of them to get along in a single cage or enclosure. That's ok. I still enjoy having them all.