When I first bought this hamster ball it was lying around rather uselessly. All of them freaked out when I put them inside and scratched furiously to get out. So I just left it out in the porch with the other hamster wheels. Momokuai was the first one to venture inside and she would use it as her personal toilet cum cycling ball. Gradually they started to develop an affinity for it and now that they realise it's THE way to get onto the floor and roll all over the house, they will bite their cage furiously to let you know it's time for the ball! Momokuai is also the only one who is smart enough to open the door. Not just once but 3 times! She knows how to get the ball into a tight corner and she will start biting and clawing at the door endlessly until it comes loose. Food is the only way to coax her out of the darkest and most-difficult-to-reach corner (like the back of the couch or fridge) of the house.