Many people encounter long-legged arthropods in their homes, often called “daddy long legs,” and wonder about their impact. Understanding the specific identities of these creatures clarifies their roles within indoor environments. This article explores the different organisms referred to by this common name and their contributions.
Understanding “Daddy Long Legs”
The term “daddy long legs” commonly refers to two distinct arthropod groups: harvestmen (order Opiliones) and cellar spiders (family Pholcidae). Harvestmen are arachnids but not true spiders, possessing a single, fused body segment. Cellar spiders, however, are true spiders with two distinct body segments: the cephalothorax and the abdomen, joined by a narrow pedicel.
Harvestmen lack venom glands and do not produce silk. Cellar spiders, as true spiders, possess venom glands and silk-producing spinnerets, which they use for capturing prey and building webs. These fundamental differences highlight why it is important to distinguish between these two groups when assessing their presence.
The Harvestman’s Contribution
Harvestmen, often found in damp, dark places like basements or under logs outdoors, play a role as generalist scavengers and predators. Their diet is quite varied, including decaying plant and animal matter, small insects, and even other small arachnids. This omnivorous feeding habit contributes to the natural breakdown of organic material and the regulation of small insect populations. They are not known to cause any harm to humans, pets, or household structures.
These arachnids navigate their environment using their long legs, which are highly sensitive to touch and smell. They do not spin webs or possess fangs, making them entirely harmless to people. Their presence in a home typically indicates a suitable microhabitat with available food sources and moisture. Harvestmen are considered beneficial due to their scavenging activities, helping to clean up minor organic debris.
The Cellar Spider’s Contribution
Cellar spiders, true spiders known for their extremely long, thin legs and irregular, messy webs, are efficient predators of other insects and spiders. They often build their webs in quiet, undisturbed corners of homes, such as basements, attics, and closets. Their diet primarily consists of flies, mosquitoes, and other small household pests that become entangled in their webs. This predatory behavior makes them natural pest controllers within a domestic setting.
A notable behavior of cellar spiders is their predation on other spiders, including those that might be considered more undesirable, such as house spiders and occasionally even black widows. While cellar spiders do possess venom, their fangs are very small and typically unable to penetrate human skin effectively. Even if a bite were to occur, their venom is not considered medically significant to humans. Therefore, they pose no threat while actively reducing other insect populations.
Dispelling Common Myths
A persistent myth about “daddy long legs” claims they are incredibly venomous but cannot bite humans due to small fangs. This is unfounded. Harvestmen do not produce venom at all, lacking the anatomical structures to inject any substance.
Cellar spiders are venomous, but their venom is mild and poses no danger to humans. While they can technically bite, their venom is not potent enough to cause harm. Both types of “daddy long legs” are harmless to humans.