Hunting spider

A hunting spider appeared on the table by my knee. Surprised by its fast movements, I jumped backwards, spilling my coffee. What is it about spiders? At a centimetre across it hardly posed a threat. I watched it, deciding not to be scared. It was hunting flies, of which there are an inordinate number here. One landed on the table, three inches from the edge. The spider sensed it, twitched by the edge of the table and then pounced, a movement remarkable in its speed. The fly was paralyzed instantly. Bravo, I thought, wondering why there was such a proliferation of flies but relatively few spiders.