Why are polar bears white?

In our explorations of the Cold Lands we have noticed that a number of Arctic animals are white. We noticed that these animals are difficult to see against the snow. These animals use camouflage to protect them.  We carried out an investigation today to explore camouflage. The children worked in pairs to search for coloured worms. This required us to observe closely and record our findings. We found the brightly coloured wool worms easier to spot than those which are brown or green as these were camouflaged against the ground. We concluded that polar bears use their white colouring to hide  from other animals, this would be helpful when hunting.