When a snake was lost at a store i worked at we managed to get it out with a live little rat. I hooked him up on a little collar made with a steel fishing lead 3 feet long and atached it to a shelf leg. the snake came out hit the rat we pulled him out from him hole, he crushed the rat when he went to eat it we tossed him i na cage, then the rat he still ate it. Took all of about 40 mins. Good luck hope you find it before it finds the ducts in your house.