Jötnar, singular jötunn, are colossal eaters.
They are rust, mould, erosion, withering, getting rid of our surplus creations. Otherwise we would over-fill our surroundings with stuff.
Jötnar are the necessary sweeping-up department.

Be careful, though, not to let them be free radicals in our body while we are still using it to live in.

Óðinn Vili  Véi  – spur for creation  –  jötnar – sweeping up  – a cycle

Same Jötnar (singular jötunn) on Youtube