I picked up 2 gorgeous young rats last week from this lovely rescue (Shelby and Soloman). They were friendly and inquisitive straight away and the carrier method Nicole recommended worked well to introduce them to our current 2 rats who are 18 months old. Shelby and Soloman are about 9 months old. I’d definitely recommend not rushing the carrier method especially with male rats. Ours are all currently still bonding in the medium sized holiday cage. Its delightful watching all 4 rats interacting with each other! I’m so pleased we were able to adopt these lovely rats.