A common question arises about these creatures: can they bite, and if so, is their bite a cause for concern? This widespread confusion stems from the fact that the “daddy long legs” label is applied to several distinct arthropods, each with unique biological characteristics. Understanding these differences is the first step in clarifying any potential risks to humans.
Understanding the “Daddy Long Legs” Label
The informal name “daddy long legs” is broadly used for at least three different types of animals. One group commonly referred to by this name are harvestmen, belonging to the order Opiliones. These arachnids are not true spiders, distinguishable by their single, fused body segment, unlike spiders which have two distinct segments. Harvestmen possess extremely long, thin legs, with the second pair often used for sensory functions rather than just movement. They do not produce silk or build webs, and their diet typically includes small insects, decaying matter, and plant material.
Another creature known as “daddy long legs” is the cellar spider, part of the family Pholcidae. These are true spiders, meaning they have two body segments and can produce silk to create irregular, messy webs. Cellar spiders also have very thin, elongated legs, often several times the length of their small bodies. They are frequently found in human dwellings, particularly in undisturbed areas like basements and cellars.
The third animal sometimes called a “daddy long legs” is the crane fly, an insect belonging to the family Tipulidae. Crane flies are winged insects that resemble oversized mosquitoes, characterized by their long, delicate legs and slender bodies. Unlike the arachnids, crane flies are insects with six legs and a different body structure.
Do They Bite and What About Venom?
The ability to bite and the presence of venom vary significantly among the creatures known as “daddy long legs.” Harvestmen, despite being arachnids, do not possess fangs or venom glands. Their mouthparts are chelicerae, which are pincer-like jaws used for grasping and tearing food, not for injecting venom. Therefore, harvestmen cannot bite humans in any meaningful or harmful way.
Cellar spiders, as true spiders, do possess fangs and venom glands. Their fangs are small but can be sufficient to penetrate human skin. However, the venom of cellar spiders is considered non-medically significant and generally harmless to humans. If a bite were to occur, it would likely result in only a mild, short-lived stinging sensation, similar to a mosquito bite, with no lasting health consequences. The common myth that cellar spiders have potent venom but fangs too short to bite humans is inaccurate.
Crane flies, being insects, do not bite humans. They lack the biting mouthparts necessary for feeding on blood or causing harm to humans. Adult crane flies typically feed on nectar or pollen, if they feed at all, and some species do not even possess functional mouths in their adult stage. They are entirely harmless to people.
Assessing the Danger to Humans
Considering the distinct biological characteristics of these three groups, none of the creatures commonly identified as “daddy long legs” pose a significant threat to humans. Cellar spiders, while capable of biting and possessing venom, have venom that is not toxic to humans. Their fangs are small, and reported bites are rare and result in only minor, temporary irritation. These spiders are often considered beneficial in homes due to their predation on other insects and spiders.
Crane flies are completely harmless, as they do not bite or sting. Their large, mosquito-like appearance can be misleading, but they do not transmit diseases or feed on blood. Ultimately, encounters with any of these “daddy long legs” are not a cause for concern regarding human safety.