Most corns don't have a problem switching from live to F/T, but there is always the exception to every rule. First, try just making the switch "cold turkey". You may get one that really doesn't care and will eat anything. Waiting a couple of days past the regular feeding schedule, to increase the snake's appetite, is always helpful. If you get a refusal, don't give in a feed a live, wait until the next scheduled feeding and try again. A missed meal in an otherwise healthy 2 yr old is not a problem. Using a pair of tongs to grab the F/T mouse's tail and making the mouse move a bit can be helpful. Always give a snake over-night to eat a mouse that is F/T or freshly killed (see below).
If you get another refuseal, get a live mouse and "thunk" it so it is fairly stunned to almost dead, but still has some leg movements. Yes, it sounds cruel, but is a step to switching a stubborn snake to F/T. Most snakes used to eating live will not refuse such an offer since they sense to movement. At the next scheduled feeding, do the same, but try to actually kill the mouse this time and offer it to the snake ASAP. The freshly killed mouse will probably have a reflex movement or two which will probably be enough for the snake. Give the snake over-night to eat. If refused, again wait until the next feeding time and repeat this step. If eaten, do this step a couple of more times and then try a F/T. If you get a refusal, give the F/T mouse an occasional wiggle with the tongs for a few minutes and leave it over-night. At this point, the snake is basically switched over if it eats. If not, again wait for the next feeding and try again.
Should you get absolute refusals, especially early on, for more than 3-4 offerings, you may have one of those totally stubborn feeders that may never get switched to F/T. And I say MAY, since the next step would be to try F/T rat pups of the appropriate size. Using a live rat pup first so your snake gets a taste can be helpful, but once a corn tastes rat, most seem to think it a special treat they can't seem to refuse. A word of warning, some corns do get hooked on rats and will refuse mice, live or F/T. This is rare, but can occur (I have one that seems to be hooked and this happened simply because I ran out of mice of the right size and only had rat to feed one week. She refused 3 consecutive meals of mice, including a live, before I offered another rat, which she ate. She did shed just before the last rat feeding, so I'm going to try the mice again at her next feeding.)
