The daddy long legs spider (Pholcus phalangioides) must surely be familiar to everyone; who has not got one in the upper corner of a room in their home? Although I see them frequently I was surprised by some of the facts I found out about them when researching my nature notes. It just shows how little thought I give to even some of our most common creatures.
Firstly, of course, it does not really look like a spider, those long legs from a very small body are more in keeping with harvestmen that spiders. However a spider it is and it builds wispy, open webs, what we know as cobwebs. The spider itself hangs upside down from the web whilst it awaits its prey to drop in. However, what do they live on? I never see any insects in their webs! If they are disturbed they can shake their bodies at high speed in the web so that they become blurred and much harder for a predator to home in on. I have seen that behaviour but I had no idea why they did it.
Daddy long legs are only ever seen indoors in the British isles, they can survive in caves and the like further south in Europe. Now I bet that if you cleared your home of them completely with the vacuum cleaner there would be one back again in no time at all! If they cannot survive outdoors where do they come from to recolonise your living room?
Finally, I do not think I have ever seen two together. Females can be present all year but males are only about in spring and summer. If there are never two together how do they mate? It must go on after dark! Again, if they cannot survive outside then surely a female must mate with one its off-spring if all the males die out in autumn.
Not much to look at but a fascinating creature that raises all sorts of questions.