By Emma Coffman, Seasonal Naturalist
Have you ever heard this before, “Daddy-long-legs are the deadliest venomous spiders, but their fangs are too short and weak to bite humans.” If this were true, we should consider ourselves lucky they can’t bite us. The reality is even more reassuring, though – this statement is a complete myth!
First, let’s clarify what exactly a daddy-long-legs is. There are actually many different spiders, arachnids, and insects we refer to by this name. Most commonly, the creature we call a “daddy-long-legs” isn’t a spider at all, but instead something known as a harvestman. While they are arachnids like spiders, they are from the order Opiliones, which is separate from Araneae, the order containing spiders.
Harvestmen have 8 legs like a spider, but they have some traits that set them apart from their web-making relatives. Harvestmen only have one body segment (as opposed to two), two eyes (rather than 6 or 8), no venom, and no silk for web–making. Seeing as they have no venom, this myth can’t be true about these daddy–long–legs.
Instead, harvestmen are completely harmless. They can mostly be found under rocks and logs or crouching on the bark of trees. From these spots, they hunt their prey. Because they feed on many of the small insects we consider pests, harvestmen are actually very helpful to us, and not dangerous to us in the slightest.
The other candidate for the subject of this myth is indeed a type of spider that we refer to as “daddy-long-legs”. The family Pholcidae contains several species of spiders that, like harvestmen, have 8 long, spindly legs and a small body. The moniker is most often used to describe the Pholcid species known as the long-bodied cellar spider, which is often found in basements or tucked-away corners of houses.
For as often as they are found in homes, you would imagine that the “most venomous spiders” would pose a threat to the humans nearby. Instead, the complete opposite is true. There is no evidence that a long-bodied cellar spider has ever used venom to significantly harm a human.
Does that mean the rumor could still be true? Their fangs could just be too small…right?
That’s not the case either. Mythbusters set out to test the myth, and the result was underwhelming: the cellar spider did bite, but it was harmless. A 2019 study confirmed their findings (even alluding to Mythbusters in their published paper) and found that cellar spider venom, while effective on insects and spiders (their usual prey), is inconsequential to humans. In other words, daddy-long-legs spiders are totally capable of biting – but their venom isn’t dangerous to us at all.
To make a long story short, daddy-long-legs aren’t the extremely venomous spiders legends would have you believe…and most of them aren’t spiders to begin with. So venture out to one of the parks and see if you can spot a harvestman.