so loki the little sod gave me and the OH a heart attack tonight. Could not see him any where, moved about the substrate and still no sign. Turned out the large 4 ft verticle log that is running from bottom to top and sat on slght slant had become his new hide. I knew I could hear noises but I cant take log out without removing the front panel of viv, so rather meanly i slowly moved a piece of card under it, and out he popped lol. at least i know he is safe and not escaped.