Cellar spider, Pholcus phalangioides
In a familiar nursery rhyme, little Miss Muffet was frightened enough by a spider to abandon both her tuffet and her curds and whey. But most likely she should have stayed put. Especially if it was a cellar spider. I noticed a cellar spider on the wall just outside my front door a few days ago. These spiders are sometimes called "daddy longlegs," reflecting their eight very long legs. This leads to confusion with another arachnid, the harvestmen or opiliones, which are also called "daddy longlegs," but are not spiders. Both cellar spiders and harvestmen have eight long legs, but harvestmen lack the distinct separation of the two body parts (cephalothorax and abdomen) that we can see in the image of the cellar spider above. This points out the difficulty of using common names for identification in biology. In this case, the same common name, while descriptive, is used for two very different creatures.
Cellar spiders are another immigrant that humans have transported around the world from its origins in Europe. Cellar spiders may be found in North America, Europe, Asia, Africa, South America, Australia, and New Zealand. They thrive in houses, particularly in dark and less disturbed areas such as basements and closets. Cellar spiders are an Anthropocene success story, adapting to human habitation and benefitting from oceanic vessels, airplanes, trucks, trains, and automobiles. Scientists are still arguing over exactly when the Anthropocene epoch started, and how it will be identified by future generations. Some say future geologists will point to plastics in an earth layer as evidence of the Anthropocene. Others mark it from the detonation of nuclear devices which have left readily identifiable traces of radiation in geological formations. But another sign of the Anthropocene will be shifts in the presence of plants and animals. Many plant and animal species have gone extinct as a result of human depredations and others, like the cellar spider, have rapidly, in geologic terms, increased their geographic distribution through purposeful and inadvertent human transportation.
I recently approached a cellar spider in its web with the thought of relocating it. As I touched the web, the spider began whirling within the web so rapidly that I couldn't tell exactly where it was. It is an amazing defensive behavior. Check it out with your own cellar spider, if you're lucky enough to have one. Or, you can also see it on YouTube - for example: https://www.youtube.com/watch?v=MS9hoK7wTx8. I mentioned that you could think of pavement ants as a kind of housekeeper, removing food spills around the house. I suppose that cellar spiders could be considered a sort of arthropod management service in your home. Cellar spiders eat whatever may blunder into their web, including moths, flies, mosquitoes, and even catch other spiders that come near the web. While they are venomous, cellar spiders have not been found to harm human beings. So there is really no downside to leaving them in whatever corner of the house they set up their web. As you can see, they are really quite attractive, can be entertaining, and catch a few of the insects or spiders that might be troubling you. Had Miss Muffet seen a cellar spider, there would have been no need for her dramatics. She could have sat happily on her tuffet, continuing to enjoy her curds and whey.