Try keeping the door to the cage open incase he is looking for a perch. Also try the clausets and anywhere with rods or hangers he could perch on. You should turn up the heat in the house to high 70s to 80. You can make some small perch setups with shoe boxes and clothes hangers and place a food item in them over night. Place them in each room and hope that he eats and perches until you find him the next morning. Good luck.