Read the four pairs below. One of them does not fit the classification the others share — which is it?

Three of the pairs join an animal to the food it lives on — the cow grazes grass, the lion feeds on flesh and the panda eats little else but bamboo shoots. The odd pair gives the hours at which the owl comes out to hunt, not what it eats, which would have been mice and other small creatures. The pair reads naturally because the owl is bound up with the night in the mind, but the group is built on food.