Transitioning from mice to rats

[MyKuLoO]

Hello,

I have a 3 ft. Jungle Carpet Python. Last week I successfully fed her a mouse and this week I wanted to start the transition to rats. So I started out with a rat pup...it was not much bigger than the mouse from last week.

My snake sniffed the rat pup and then both retreated to their corners and just sat there for hours. I heard that carpets don't know or like the smell of rats at first so I tried a trick I heard about and gave the rat pup a bath in chicken stock mixed with water. I had heard that this makes the snake like the taste better.

This did not work either. Any tips?