Are daddy long leg spiders poisonous? — Rianna’s student essay

Are Daddy Long Leg Spiders Poisonous?

I have chosen to tackle the question ” Are daddy long leg spiders poisonous?” To ensure I am answering this question correctly, I will briefly explain the difference between an animal being poisonous versus being venomous. According to “Britannica,” they describe the difference to be “the term ‘venomous’ is applied to organisms that bite (or sting) to inject their toxins, whereas the term ‘poisonous’ applies to organisms that unload toxins when you eat them.”

When speaking about daddy long legs, there are two insects to consider: the Opilionids arachnids and the Pholcids. Taken from the article called “Are Daddy Long Legs Poisonous” on LiveScience, they describe the Opilionids arachnids to have “pill-shaped bodies with eight legs.” 

Taken from the U.S Department of Education, these are not spiders, but actually “arachnids” which are most closely related to the scorpion. They do not produce silk for webbing and they have one pair of eyes, which regular spider have six to eight pairs of eyes and of course the ability to produce silk. 

Specifically for this species, they do not have fangs, therefore do not have to subdue their prey with venom. The Opilionids arachnids feed off of decomposing animals and plants.They can, however, produce poisonous secretions from their bodies that can harm smaller animals if posed a threat.

Therefore, from the definition, they are poisonous to small animals. Going on to the Phlocids, they are considered spiders. They have similar physical characteristics to the Opilionids but Phlocids are more oval shaped and have a less reddish color. “DiscoverWildlife” says these spiders produce webs and capture their prey like many other spiders.

daddy long legs

They have a specific technique the way they capture their prey by vibrating their web vigorously to make them seem invisible to their prey. They do have fangs that can inject venom and they eat on smaller insects and spiders. There was an interesting study done by the famous show “Mythbusters” regarding these spiders. This show is known for “busting myths” and proving if common myths are true or false.

 In 2004, they decided to perform an experiment, where they would make a Phlocid spider bite one of the host, Adam Savage. They stuck his arm into a clear cylinder filled with daddy long legs in hopes of a bite. After he was bitten, he was perfectly fine. He described the bite to have a mild burning sensation for a few seconds. This proves that these spiders are venomous, but not enough to harm us.

What about poisonous? To sum it up, taken from the article “The Most Misunderstood Spiders” on BugGuide, they explain how there is no scientific proof these spiders are poisonous because scientist cannot preform these experiments due to “a variety of reasons including Amnesty International and a humanitarian code of ethics.” In summary, we are not scientifically sure if daddy long legs are poisonous to humans but we are sure they are poisonous to small animals. Yet, because of the relative size of the spider compared to human, we can infer that the toxins released by these spiders will not be enough to harm humans permanently. So yes, daddy long legs are poisonous depending on the size of the animal you are referring to.

Author: Rianna Dixon

University of Houston

Student Scholarships

Every year Thrive Pest Control hosts an essay contest and the reward is a 1-year scholarship at a 4-year university in the United States. This blog post is one of those scholarships.