Recently when in the Arctic, I came across these two polar bears - mother and 2nd year cub making their way across the snow.
I watched them for some time and became transfixed by the symmetry of their walking. It reminded my of two soldiers maintaining the same distance from one another and "walking in time".
They continued to walk like this for sometime and appeared to showed no apprehension towards my presence - although I am quite sure they new exactly where I was at any particular time.
LEFT: Polar bear mother and 2nd year cub make their way accross the snow in Canada.