Fridge Magnet - Missing Termometer

One of my Mum's fridge magnet collection was missing. She bought it at Adelide, AU. She said it is ok. But there was very wierd and mystery incident in my house when a termometer in one of my Mum's fridge magnet was missing. Who on earth really want to steal it? And for what purpose?

Well, I think that naughty cat at the back of our house who stole it.