Dexter was a wheaten burmese.
When I adopted Angel, Rocket Man and Sgt. Pepper, the rescuer who had them asked me if I'd like to take Dexter too.
He had previously been used for breeding, but was proving difficult with other males. His owner thought he would be better off at a smaller rattery, and possibly get castrated so he could live with females, which he had previously gotten on wonderfully with.
I tried Dexter with my males to see his behaviour, and it seemed to be fairly mixed. On some occasions, he settled down with them and slept in a pile, indicating he could possibly be ok with other males with enough work. However, on other occasions, he would try to attack other rats just for passing by him, so he was not reliable.
It became clear that he could not be trustworthy in a group. It was a shame, as sometimes he would be fine, then the next moment he would be attempting to inflict damage.
I had Dexter castrated, and intended to put him in with the girls, feeling he may take better to females. This worked, and Dexter went on to live a happy life with his harem of ladies!
Dexter developed an inoperable internal mass, which was the cause of his death.
Why Dexter? This is what he was called when I got him.