Fear, the Capacity for

I wonder why the human capacity for fear far exceeds evolutionary necessity. It is like some snakes. The Fierce Snake, a variety of the Australian Taipan, could reportedly kill 250.000 mice with one bite, if it were inclined to do so. Supposing the average house mouse has a girth of a modest 5 centimetres in diameter and the Fierce Snake uses each of two fangs to penetrate seperate stacks of mice, he would actually need a gape 6¼ kilometers wide to reach his full killing capacity. As far as I'm aware there is no SI unit for horror (possibly Ho., though), but it would be fair to assume that the number expressing the the amount of horror our capacity for fear is capable of dealing with is equally ridiculous.

Picture: a modified screen shot from the 1962 horror picture "Carnival of Souls".