I was afraid of that (that he's little). Remember how intimidated they are on the floor...they look for things to crawl into & avoid being out in the open. Before you
start searching in a widening circle from the point of escape, I'd cover those heating vents with fabric (tacked up) so the air goes thru but hopefully not a snake. Check
in & around & under all furniture...snakes go under couch cushions & into the back of dressers (underneath the drawers, or up inside), and any furniture with a faulty
lining underneath is especially "welcoming" to a snake...box springs, upholstered chairs/couches. And of course, CLOSETS. Even behind books in bookshelves... You
may want to seal off the room he escaped in, just in case he's still "local", & start search there. DON'T GIVE UP!