Yes, It was my fault, didn't clamp the lid securely :( . Anyway, I have located him, I just can't get him. He is sitting all comfey behind a wall unit. He can't get under it, so he is in plain view behind it. It is a massive unit, so taking it apart is not an option, and I can't reach him, to far in. He has been there since last night, and even overnight never ventured out. I even tried leaving 3 mice for him , right next to the wall unit. Any other suggestions would be appreciated. I papered the living room up, a few feet high, to try to keep him from leaving. I don't think he can climb straight up kraft paper, could he? There is no other ways out, so hopefully I'll get him soon.