Frogs are brilliant hiders - I once looked in my tank to find none there...for the life of me i couldn't work out how they escaped. I pulled the tank away from the wall and that's when I saw 7 wee bodies stuck to the glass hiding behind the background climbing wall I had. I had thought there was no room behind there hence why i hadn't looked behind there before!

I hope that's you found the frogs and not just one! - If you still haven't found the other try putting some carrier bags in various places around your house. If the frog goes hunting you may just hear rustling if he/she climbs over a carrier bag!

Being a tree frog remember to look up high, perhaps in folds of curtains or on blinds?