The term “daddy long legs” commonly describes long-legged arachnids often found around homes. This widely recognized name frequently leads to confusion regarding their true nature and whether they possess venom. A pervasive myth suggests these creatures are highly venomous but cannot bite humans due to small fangs. Understanding the scientific distinctions among them clarifies this misconception.
Identifying “Daddy Long Legs”
The common name “daddy long legs” refers primarily to two distinct types of arachnids: harvestmen and cellar spiders. Despite both having long, slender legs, they belong to different scientific orders and possess unique characteristics.
Harvestmen, belonging to the order Opiliones, are not spiders. They have a fused, oval-shaped body that appears as a single segment, unlike the two distinct body segments (cephalothorax and abdomen) found in spiders. Most harvestmen have a pair of eyes situated on a raised knob-like structure near the middle of their body. They also lack silk glands and do not spin webs.
Cellar spiders, members of the family Pholcidae, are true spiders. They exhibit the typical spider body plan with two distinct segments, a cephalothorax and an abdomen. These spiders construct loose, messy, irregular webs, often found in corners of rooms or basements. Cellar spiders typically possess eight eyes, arranged in specific groupings.
Dispelling the Venom Myth
The myth about “daddy long legs” being highly venomous but harmless to humans is unfounded. Harvestmen do not possess venom glands at all. They are not equipped with fangs for injecting venom, and their mouthparts are designed for tearing and consuming food, such as small insects, fungi, or decaying matter.
Cellar spiders, while true spiders, are not dangerous to humans. Like most spiders, they produce venom, but their fangs are too small and their venom too weak to pose any threat. Bites from cellar spiders are rare and generally result in no significant reaction beyond a minor, localized irritation, similar to a mosquito bite.
The confusion likely stems from the shared common name and a misunderstanding of arachnid biology. Both harvestmen and cellar spiders are harmless to humans and control insect populations within their habitats. Their presence in homes is usually due to seeking shelter in dark, undisturbed areas, and they are not considered a pest.