You've probably heard this playground legend: Dad's long legs are the most venomous spiders in the world, but their fangs are too short to bite you. Is this really true?
The short answer: no. But to reach that answer, we need to get a few things clear.
"First, what do you call a father's long legssaid Rick Vetter, a retired entomology researcher at the University of California, Riverside. Vetter has been debunking this particular myth for years.
Related: Could humans ever be toxic?
The problem is that the term "daddy longlegs" is used in everyday speech to refer to at least three different animals, only one of which is a real spider.
The animal is also known as a basement spider in the family Pholcidae. Like other spiders, it has two body segments, eight eyes and fangs, complete with venom ducts and venom glands.
Then there are the harvestmen, who are spiders in the order Opiliones. Unlike spiders, these animals have a single body segment and only two eyes, and they have no fangs or venom glands.
"Harvesters have small gripping mouthparts," Vetter told WordsSideKick.com. "They look like little pinches. And they're mostly used to tear prey, dead animals and dirt apart."
Finally, there are crane flies, in the family Tipulidae. These are insects, not arachnids, and their long bodies and wings make them look like oversized mosquitoes. But unlike mosquitoes, they can not bite you. This is because many species of crane flies have no mouthparts at all. They exist in their adult stage for just a few days - enough time to mate and lay eggs.
Clearly, Dad's long legs are not just one thing. But what about their poison? Crane flies have none, so for them this legend is clearly false. Harvesters are not married either - they are married. Where poison acts by being injected into the target, poison acts either by being ingested or through local contact. When harvesters are disturbed, they spray or line themselves in one dark, foul-smelling chemical mixture designed to ward off parasites and predators. Although this substance can kill spiders and insects, it is certainly not the world's most toxic poison.
It leaves us with basement spiders, the flock's only true spiders. These can actually bite people. Their fangs are similar to those of the brown recluse (Loxosceles hermit), said Vetter, who is notorious for his potentially deadly bite to humans. But this is where the similarities end.
"I am not aware of any publication showing that pholcid spiders cause a toxic effect in humans," Vetter said. "I think a scientist was working on it a bit and he had a little black mark for a day or two and said, 'It's not that big of a deal. Definitely not the most poisonous spider in the world. "
Poison analysis has confirmed this. On a "Mythbusters" episode from 2004, which was later documented in a 2019 study, arachnologist Charles Kristensen reported that he injected mice with venom from either basement spiders or black widow spiders. The black widow poison had a much more potent effect.
So if this legend is false, then why has it persisted all these years?
"It's a really good question, and I really do not have an answer to that," Vetter said. "I think what's happening is that it's something someone once said and there was never enough knowledge to refute it. So it's just going on and on. And people love scary stories."
Originally published on Live Science.