That's the million dollar question that you'll get a lot of differing opinions. A lot of it has to do w/ how often you are offering (space it out so your not creating stress by offering it too soon), trying all the tricks (hair dryer, scenting, feeding at night, etc..) and then making sure your BP is not showing a significant weight loss. They can go a long way w/o eating. I was pretty frustrated and almost gave up on the rat idea but I kept at it and finally converted mine. It was an amazing feelingGood luck....