A widespread myth holds that daddy longlegs, also known as granddaddy longlegs or harvestmen, are the most venomous spiders in the world. We're only safe from their bite, we are told, because their fangs are too small and weak to break through human skin. ... So, for these daddy longlegs, the tale is clearly false."Dec 8, 2011
In the Southern United States as well as some parts of Canada and the United Kingdom, the crane fly is also sometimes called a daddy longlegs, according to The Burke Museum of Natural History and Culture. This distinctive bug, with six long legs and two large wings, is not a spider, nor an arachnid, but is an insect.Dec 24, 2014
Scorpions are arthropods, they have eight legs, two pedipalps, and a tail with a venom-injecting barb. Scorpions have two venom glands that produce venom used in hunting and self defense. Scorpions do not have bones instead they have an exoskeleton made of chitin, which is similar to the shell of a shrimp.
They look a lot like crabs and many have the word 'crab' in their name, but are not true crabs. Anomurans can be told apart by the number of legs: crabs have ten legs, including claws, while the last pair of an anomuran's legs is hidden inside the shell, so that only eight legs are visible.