I agree with KMG, if it's your only snake then why chance wasting a feeder unless of course you feed live. As for the snake every one is different I have some that will eat even when in blue, and I have others that absolutely refuse when even the slightest hint of pre shed is indicated. If you have several snakes then it becomes easier, I have several large females that I know will pound down a treat between normal feedings. I know of several guys who also keep a Retic in their collection and refer to them as garbage cans as they will eat anything and everything thrown into their tubs.