I am an expert on this unfortunately. My BC got outside so.... but I scoured the net and found and used the best options. I found my BP 2 times using this method. Put a space heater near a wall. One that wont be able to burn snakey. Put several blankets in a half circle around space heater. Check them every morning and night.

I have also learned these nifty tricks. This one helped keep hope alive because I could see he was around..but he was good at getting out of it. If you are lucky it will stick to him and you can follow the trail. Leave long pieces of blue painters tape along floorboards and places you think your snakey may cross. Even if your snakey is a tape escape artist like mine, it can give you an idea of his location. Mine would have the tape all crinkled in the morning in a way that left no doubt it was him.

Put flour or talcum powder along doorways to track location and direction. If you are desperate to find your beloved, then go to the dollar store and buy about 10 big bottles and sprinkle along floorboards and doorways of entire house. Beware because it does rise and coat everything but if you need to it is worth it and you will be able to track any movement. If you suspect that your snakey has made it to the outside...don't do this. Cleanup is a little devastating at that point but if you are positive snakey is indoors then you will locate the critter. Drastic times can call for drastic measures.

If you love your snake but can't go to that extreme... put plastic baggies along baseboards and in corners. They make a loud rustling noise that snakes don't try to avoid. They even play in the bags so it is a good method as long as you are awake. If you have a limited number of bags, crumpled up newspapers also work.

If you have a basement, look in the rafters every day. They will chill up there where it is warmer and even if you look 10 times a day...on the 4th week you just might see snakey.

I left food out all the time and it never worked. Just keep looking.