What have you been trying to feed it so far? Do you know if it was eating live or frozen/thawed before? On the one hand, most snake keepers these days will try to maintain there animals on frozen rodents which have been properly thawed. Some snakes, often babies, will not take prekilled prey right away, but will accept live. BUT...if your snake has been eating frozen/thawed pinkies in the past, a live pink may have startled it. I was suggesting frozen/thawed, but if what you have on hand is live, then still try cutting the head off...that would certainly qualify for prekilled.
What are the day and night temps in your home right now, and do you have any supplemental heating for the snake? My home here in Ohio is starting to warm up to the point where I start unplugging my heaters, but lots of folks use them year round, especially if they use air conditioning in there house.
Is your snake "sniffing" around at the prey, maybe pushing it around, just not eating? That's what my little snow corn did before I used the beheading trick. I placed her in a small deli cup with the pink, and she ate it right away.
If your new snake is as small and frail-looking as you say, you really want to get a meal in him. Go ahead and try the headless pink thing, and let us know how it goes. If you don't have any extra heat, you will want to consider it, especially if your house temps are cool. A warm side and cool side for your snake's cage is the best setup, but if your house gets and stays quite warm in the summer, you might be able to get away with the normal day/night fluctuation in temps. Let us know how you have your snake set up right now, and we will try to make suggestions.
Again, check out some of the old posts below...you will learn alot. Good luck, and let us know when Eden eats her first pink.
Duffy