When I first switched, I still offered every week but she usually only ate about every 10 days. I got a little rodent cage and just kept the rat if she didn't eat it and then offered it again three days later and she'd usually eat it then. After awhile, she started taking it every week. I don't remember exactly when I switched to rats, maybe 8 months ago? But at this point she takes them immediately every week just like she did when she was on mice.