leave your tank all set up with the heat lamp on and put a mouse in there or if you can get your hands on some used gerbil or rat bedding for extra sent..... if it is cold he will return to the tank and also he might be hungry and go back for the food. I lost mine and he came back 4 days later and i found him crawling back into his cage... they dont go far from the cage just be patient they dont go further than about 15 feet away from there enclosure. check the same spots every day, i must have check my dresser 100 times and sure enough i found him in the dresser crawling to his cage