Rats are more convenient for the reasons stated. Easier to feed the right size.

My girl was a mouser til she hit 300gm a few weeks ago. She has taken her first two rats without thinking twice, perfect transition. She has always had a fantastic feeding response too, absolutely pounds them every time.

So, I wish you a prefect transition! Hopefully you lucked out like me and got an unusual BP that will devour anything you dangle in front of it.