Daddy Long Legs: Separating Fact and Myth

By Sydney Krisiewicz   Muhlenberg College Class of 2015

A typical Harvestman Dalavich

   CC License Some Rights Reserved

If you grew up in Pennsylvania like I did,  then I’m sure you’ve seen Daddy Long Legs.  Maybe you have even picked one of them up. When I was a child I had a lot of fun picking these guys up off of trees and watching them walk around in my hand. That is, until I heard the infamous rumor about them. Maybe you have already heard it before...   “Did you know Daddy Long Legs are the most venomous spider in the world? Their fangs are just too small to pierce human skin”. Terrifying stuff! I plan on clearing up this misconception about the Daddy Long Legs and (spoiler alert!) they’re not venomous. 

First of all, let’s make sure we’re on the same page. There are a couple different critters that the title “Daddy Long Legs” could be referring to. The first is not even an arachnid, it is an insect: the crane fly. This guy looks like a giant mosquito but it is totally harmless. The second “Daddy Long Legs” refers to the cellar spider—which, not surprisingly, are found in basements as well as garages. The most venomous myth does not apply to these guys either; they are not known to bite humans. 

Lastly, there is the PA version of a Daddy Long Leg: the harvestmen. Where do harvestmen fit in on the grand scheme of things? Well actually, they aren’t considered spiders! (It is hard to be considered the world’s most venomous spider if one doesn’t even meet the qualifications). While both groups are arachnids, harvestmen are found in their own class—opiliones. Think of them like cousins of spiders. When you are trying to determine if a spindly-legged arachnid is a spider or a harvestman, a dead giveaway is the shape of their body. Spider’s bodies will have two connected segments but harvestmen just have one pill-shaped body. 

Now, I know what you’re thinking: so they’re not true spiders but are they still venomous with fangs too tiny to pierce human skin? The answer is no! They do possess fangs, and those fangs are indeed too small to pierce human skin, but even if they could, harvestmen do not have venom glands or hollow fangs capable of delivering any venom. In fact, many species are scavengers or omnivores feeding on a wide range of food from insects to plants to fungi to dead organisms or even bird poop! 

While they are indeed venom-less, these guys aren’t defenseless. In fact, one of their main defenses is an oral secretion. This fluid is part of how they eat—harvestmen don’t swallow solid food but will grind it up in their mouth and digest it with this fluid. If attacked—say by a spider or their main enemies: ants—they will produce a drop of this liquid and dip their legs in it then use their long legs like weaponized paintbrushes to wipe this fluid onto the attacking creature, which will generally repel them. 

Mehran Moghtadai  CC License Some Rights Reserved

Next time you encounter what appears to be a spider with a body like a tiny pill resting atop spindly long legs—fear not! It is most likely a harvestman which could not hurt you if it tried! And if your friends try to convince you otherwise, demonstrate how fearless you are and impress your friends by picking one of them up! Just be gentle when you do—harvestmen are known to practice a defense mechanism, leg autonomy, in which they’ll voluntarily detach a leg to avoid predation. So take care as you pick them up or you might find yourself holding a detached leg as the harvestman makes a getaway!

This post by Sydney Krisiewicz is licensed under a Creative Commons Attribution 4.0 International License.