The above video that has recently been circulating on the internet showing a terrifying cluster of spiders is actually a harmless cluster of opillonids, also known as “Daddy Long Legs” that are simply trying to stay warm. In Greek we call them phalanges.
The nickname "Daddy with Long Legs" and the appearance of the creepy animals contributed to the confusion.
Opillonids, according to the UC Riverside Department of Entomology , are arachnids belonging to the genus Opiliones and are not even spiders.
Opillonids, also called harvestmen, consist of one main body segment – as well as legs – while spiders have two main body segments: the cephalothorax and the abdomen.
Harvestmen are not poisonous to humans at all. Mr. Paglo Barroeta, who first posted the video online, was not in any danger when he pushed the cluster with his finger.
As for the formation of the cluster, arachnologist Ricardo Pinto-da-Rocha, in his book "Harvestmen: The Biology of Opiliones ," states that harvestmen are sensitive to temperature changes and cluster formation is ineffective for avoiding water loss. The super-thin legs of harvestmen organisms do not offer much protection, so these arachnids tend to gather all together, to maintain warmth and moisture and to protect themselves from possible predation.
