The common name “daddy long legs” refers to two distinct types of arachnids: harvestmen (Order Opiliones) and cellar spiders (Family Pholcidae). While both are known for their notably long, slender legs, they belong to different groups within the arachnid class and possess unique biological characteristics. This article will focus on these two arachnid groups, exploring their dietary habits, how they acquire their food, and addressing common misconceptions about their potential danger to humans.
Their Varied Diet
Harvestmen are primarily omnivores and scavengers, consuming a wide array of organic materials. Their diet includes decaying plant and animal matter, fungi, and even bird droppings, highlighting their role as decomposers in many environments. They also opportunistically scavenge on dead insects and other small invertebrates. While not true predators, some larger harvestmen species may occasionally prey on small, soft-bodied live invertebrates such as aphids or mites.
Cellar spiders, in contrast, are predatory arachnids that actively hunt other arthropods. Their diet commonly consists of various insects, including mosquitoes, gnats, and flies. They are also notable for preying on other spiders, often tackling species much larger than themselves, such as wolf spiders or even more medically significant spiders like black widows.
Hunting and Feeding Strategies
Harvestmen employ a scavenging and opportunistic feeding strategy, not relying on silk or venom to capture prey. They primarily use their exceptionally long legs as sensory organs, tapping and feeling their surroundings to locate food sources. Once food is found, they grasp it with their chelicerae, which are pincer-like mouthparts, and tear it apart to consume solid particles.
Cellar spiders, being true spiders, construct irregular and often messy webs to ensnare their prey. When an insect or other arthropod becomes entangled, the cellar spider will bite it to inject venom, which helps subdue the prey. They then wrap their catch in silk before consuming it. Some cellar spider species also exhibit a clever hunting technique where they vibrate the webs of other spiders, mimicking the struggles of trapped prey to lure the web’s owner closer before attacking.
Are Daddy Long Legs Dangerous?
A widespread myth suggests that “daddy long legs” possess highly potent venom but are harmless to humans due to fangs too short to penetrate skin. This is unfounded. Harvestmen are not venomous at all.
Cellar spiders, while venomous, are not considered dangerous to humans. Their fangs are indeed very small, and their venom is not medically significant, meaning a bite would typically result in a mild, localized sensation, if anything. The myth of their “deadly venom” is a misconception, often arising from their ability to prey on other, more venomous spiders.