My favorite trick is the flour on the floor (only works for hardwood or tiled floors). It lets you know what room they're moving around in. Set some by any holes in the walls if you have them too, just to make sure.
You can try the plastic baggie trick. Get stop n shop bags, and bait them with reaaaallly smelly rats (crack the heads open if you have to) and set them up in places you think he might be hiding. When and if you hear the bag crinkling, nab your snake.
The best trick is the bottle trap. Get a big old soda bottle, and poke air holes in it. Get a really smelly pre-killed rat (the fresher the better, it's more tempting and won't rot over the heat), and put it in the bottle, and then put that on a uth mat. The heat will make it smell even more, and it will lure your snake out. The snake will crawl in, eat the rat and be too fat to crawl back out if you're lucky.
Good luck! I hope you find your little guy.![]()