We appear to have a new 'invisible' critter

Well, according to Mocha anyway...she's got a 'thing' for lying on her side next to a piece of furniture which has a wee gap between it and the floor and reaching under it for something.

It's really funny to watch, she lies pawing under there for a bit after our new invisible critter and then looks at me as if to say 'what? there's a mouse under there...really'! So far this 'mouse' lives under my bed, but would appear to have made it's way to under the desk in the living room! Just waiting for it to move to under the couch Maybe it's the bedcover mouse she's after...