Mine both used to do that, one more than the other. I made a point of not putting them back right after they had done it as I thought it was a 'put me back' stunt! They seem to have grown out of it as they have been handled more (my female was pet store bought and as a result not handled and she is VERY fast and skittish!) Having said that she has got me twice this last week, lol! I prefer being peed on to being bitten though - they both went through a phase of nipping too. Another thing they thankfully seem to have grown ut of cos it would hurt now they are adults!