Everyone knows what a Daddy Longlegs is, or thinks they do. In fact, there are two different groups of animals with the name Daddy Longlegs, both Arachnids, but in different orders. (Scorpions are in yet another order of Arachnid.)
One kind of Daddy Longlegs joins other true spiders in the Order Pholcidae. Also known as Cellar Spiders, they have two body parts: a cephalothorax to which the eight legs are attached, and an abdomen. They have eight eyes, which are mostly clumped in front, and they spin silk webs.
An article on the University of California, Riverside website explains,
The most common pholcid spiders found in U.S. homes are both European immigrants. Pholcus phalangioides is a uniformly grey spider with rectangular, elongate abdomen and is found throughout the U.S. Holocnemus pluchei also has a rectangular, elongate abdomen but has a brown stripe on the ventral side (the belly side – which is typically directed upwards since the spider hangs upside down in its web) which covers its sternum and is a stripe on the abdomen. These spiders are very common along the Pacific Coast and into the southwest deserts.
Are these spiders venomous? Like other spiders, they produce venom, but since there are no accounts of a pholcid spider biting a human, much less causing injury, no one has ever bother to test their venom to see if it can hurt us. Odds are they’re harmless—most spider venom isn’t compatible with our body chemistry, so they can’t hurt us although they might injure other animals. (Of course, notable exceptions include the Brown Recluse and various widow spiders, which are dangerous to humans.)
Then there are the other Daddy Longlegs—the ones I think of when I hear that name. They are in the Order Opiliones, and are also known as Harvestmen. Unlike true spiders, they only have one main body part, which is spherical and slightly segmented toward the rear. All eight legs attach to this main orb. Also unlike true spiders, these Daddy Longlegs only have two eyes, and they do not produce silk.
They may not be true spiders, but that fat globe of a body surrounded by long, thread-like legs is enough to give most people the creeps. Still, there’s really nothing to be afraid of. Daddy Longlegs eat decaying plant and animal matter, although they won’t turn down easy-to-catch prey. They’re most often found under old logs or stones. They don’t have any poison glands, so they can’t be venomous.
I was really glad to learn this, because I have lots of Daddy Longlegs in my garden. They skitter up and over my legs when I’m weeding, causing me to spring up with a yelp and a shudder. I’ve also seen them striding across large boulders in Colorado’s evergreen forests. Maybe learning more about these innocuous creatures will help me be more tolerant in the future.