Like I said, you can "sell" you feeders/ pets as long as you put them in the "general for sale" section, otherwise, if you want to put them in the "pets" section, you will have to say it is a re-homing fee.
Basically your ad should look like this:
Hello,
I have a couple of rats/ mice that need to be re-homed. They are various sizes, and are becoming costly and time consuming. I no longer have the time to care for them and they need to go, they are my pets, but can be feeders if need be. I am asking a re-homing fee of "--" each.
Thank you,
_______
I have found that if you are polite in your adds with the "Hello" and "Thank you" that they will last a little bit longer. But, any how, that is how I used to write up my adds, so hopefully that will help someone out.
Good luck guys!