Secure the room, then think like a ball python
The good news buried in a bad moment: an escaped ball python almost never goes far. This is a shy, ground-dwelling snake that hugs walls, avoids crossing open floor, and stops at the first warm, tight, dark gap that feels safe. Work on the assumption that he is within a room or two of the enclosure, quite possibly still in the same room, and search slowly rather than ransacking the house — a python wedged behind a heavy appliance can be hurt by furniture dragged carelessly across the floor.
Start by closing the door of the enclosure room so the search area stops growing. Look carefully at exactly how he got out — a lid corner lifted, a cable port left unsealed — because that opening tells you the size of gap his head can pass, and every gap that wide in the room is a candidate hiding route.
The hiding spots a ball python picks first
Ball pythons follow edges, so search the perimeter of each room at floor level before looking anywhere central. Get right down with a flashlight and check behind and under the refrigerator, where motor warmth runs all day, around water heaters and hot pipes, behind the washer and dryer, and inside the warm backs of entertainment units crowded with power bricks and cables.
Check the awkward places too: inside sofa frames and recliner mechanisms, beneath low dressers, inside piles of stored blankets, and along any radiator or heating vent. A ball python can flatten into a space that looks far too small, and a motionless coiled snake in shadow is easy to look straight past, so move each object once, check it thoroughly, and set it outside the room so you know it is cleared.
Set the room up as a trap tonight
Ball pythons move at night, so let darkness work for you. Place his familiar hide on the floor against a wall near the enclosure, a water bowl beside it, and gentle warmth under one end from his usual heat source, used safely outside the tank. A hide that smells like home, sitting warm in the dark, is the most inviting target in the room, and many keepers find their snake settled in or beside it by morning.
To learn whether he is moving at all, lay a thin line of flour across the doorway and along wall edges, and tape a few crinkly plastic bags flat along the baseboards. Disturbed flour by morning tells you which room he is active in, and a bag rustling at two in the morning, checked quietly with a dim flashlight, can end the search on the spot.
When you find him, and if two nights pass
Lift him slowly with both hands supporting his body, expect him to be cold and possibly defensive after time loose, and return him straight to a secured enclosure with fresh water. Then fix the actual failure: clips on every lid corner, cable ports sealed, and no gap wider than his head anywhere in the setup — a ball python that escapes once has learned the route and will test it again.
If two nights of trapping turn up nothing, widen the search room by room and consider that he may have reached a wall void or slipped down into a basement or garage gap. Cover the outside possibility too: tell immediate neighbors plainly what he looks like, that he is a harmless pet, and that he is most likely hiding under a porch or a woodpile. If your ball python does turn up in a neighbor's yard, his KinsLe profile carries the Lost Pet Alert System at no cost, with the alert shown on a map and a direct message route back to you.