If you are really afraid you are going to lose the one, force feed it a mouse tail. Use about a 1.5-2" segment of adult mouse tail, fat end first. slide the tail in the side of the baby's mouth. Slip it down about half way and pause to see if he will just swallow. Sit motionless until he either swallows or tries to gag it out. If he won't start swallowing, slide it about 3.4 of the way down. He will eventually swallow it.
When I feed tails, I offer the food item first and give the baby 1-2 hours to feed. If not, he gets a tail. Try again in 3-5 days.
Another thing you could try is slap feeding. Look down in Susan's private forum. There is a link to a video. You do NOT have to use a live pink. I would NOT use a live pink. If you restrain the baby so about an inch of his neck is free, and touch/jab him in the neck, with the pink aimed so when he strikes at it, it will end up in his mouth, you can get him to eat. It takes a LOT of patience. Once he strikes, freeze and do not move a muscle until the pink is all the way down. They can and will spit it out even when it is completely gone, if frightened. If he strikes, and then spits it out, keep trying until he either eats or won't strike any more. IF the baby will strike, and 95% of them will, you can get him to tease feed.