The common term “daddy long legs” often evokes questions about their potential to bite humans. This article aims to clarify whether these creatures, frequently found in homes and gardens, pose a bite risk. Understanding their biology helps dispel widespread myths.
Identifying “Daddy Long Legs”
The name “daddy long legs” can refer to at least two distinct types of arthropods, leading to confusion. One group is harvestmen, belonging to the order Opiliones. These arachnids are not true spiders, possessing a single, oval-shaped body segment where their cephalothorax and abdomen are broadly joined. They typically have two eyes on a raised mound.
The other common “daddy long legs” are cellar spiders, which belong to the family Pholcidae. These are true spiders within the order Araneae, exhibiting the characteristic two-part body of a cephalothorax and a separate abdomen. Most cellar spiders have eight eyes, often arranged in two groups of three with a pair in the middle, though some may have six. Both are recognized by their exceptionally long, thin legs, which contribute to their shared common name.
Do They Pose a Bite Risk?
Whether “daddy long legs” bite humans depends on which creature the term refers to. Harvestmen (Opiliones) do not possess fangs or venom glands. Their pincer-like mouthparts are designed for tearing food, not piercing skin. Consequently, harvestmen are incapable of biting humans or injecting venom.
Cellar spiders (Pholcidae), as true spiders, possess fangs and venom glands. However, their fangs are quite short, typically around 0.25 millimeters, making it difficult for them to penetrate human skin. While venomous, their venom is very weak and not medically significant or harmful to humans. They are generally not aggressive and are unlikely to bite unless provoked or trapped.
Why the Common Misconception Persists
The misconception that “daddy long legs” are highly venomous but cannot bite humans is a widespread urban legend. This myth often suggests their venom is among the world’s most potent. However, scientific evidence refutes this claim, particularly for harvestmen, which lack venom entirely.
One reason this myth endures is that cellar spiders prey on other spiders, including black widows. This might lead some to conclude cellar spiders possess strong venom to overcome such prey. However, cellar spiders often rely on their long legs and silk-wrapping abilities to immobilize prey, rather than solely on venom strength. The confusion surrounding the term “daddy long legs,” combined with a fear of spiders, contributes to this unfounded belief.