Being so far north, much of region - some 146, 000 square km - is covered by glaciers and ice caps (a type of ice field where glaciers flow off in many directions).

BBC: Canadian glaciers face 'big losses'

On the other hand, for a compound eye to be effective, its elements must point in lots of directions, in order to cover a wide visual field.

ECONOMIST: Brittlestar eyes

The magnetic field lines are like the two lanes of traffic on a busy road: close together, but pointing in opposite directions.

ECONOMIST: Hot stuff