Born on 2 December 2014 these polar bear cubs have developed into two independent individuals after six months. They don't need Mum anymore, they have each other. For some serious roughhousing, for fun and a swim, although one needs more persuasion than the other to plunge into the pool.  Polar bear white is not the colour they think is suitable for the Rotterdam Zoo situation, so some rolling around on the ground gives them a nice camouflage colour – impersonating a grizzly. Too bad it wears off in the water though.By the way, when they get really really tired they still fall asleep against Mum.