This house on a hill in the west of Ireland sits empty most of the year. When we arrive in summer every nook and cranny has its spider, Pholcus phalangioides, sometimes called "daddy-long-legs."
They are harmless things, but left to themselves they would overrun the place. So we go about sucking them up with the vacuum cleaner.
Except for the few I keep under the shelf above my desk, where I can watch and learn their habits.
If I touch one with the tip of a pencil, it flings itself into a dervish dance, turning itself into a blur. It must be a defense mechanism, selected by evolution many thousands or millions of years ago, probably not a bad way to defend yourself if you are all legs.
Pholcus phalangioides's dilemma is not unlike that of other creatures on the planet. Natural selection prepared them well for the rough-and-tumble of non-human predators, but not for the long black snout of the Hoover.