Firstly if it was a boy you would know, its pretty hard to ignore, rats have large testicles. Secondly of course its not friendly, you just dragged it out of its home and scared it half to death. Rats are cognitive beings and need time in order to learn to trust you. I definitely don't think you should keep it as a pet. Freeze it or feed it.
Dont start breeding until you do more research. At the very least gain some knowledge on the animals you are about to create and kill.