My male chins are not getting along.

I have two male chinchillas, One I adopted from a get store as a baby and the other I adopted from a girl that was not fit to take care of him, she said he was eight months at the time but he looked huge. At this time our first chin was around 4 months old. I did the normal bonding process when I brought my second chin home. And everything went well. They have been together for over two years. Recently ive noticed the older chinchilla was now getting to be smaller than the younger. (The...

My male chins are not getting along.