The term “daddy long legs” is commonly used, yet it often leads to questions about the creatures it describes, particularly regarding their nocturnal habits. Understanding the activity patterns of these animals requires first clarifying which specific arachnid the term refers to, as it encompasses more than one distinct group.
Clarifying What a “Daddy Long Legs” Is
The name “daddy long legs” typically refers to two different types of arachnids: harvestmen and cellar spiders.
Harvestmen, belonging to the order Opiliones, have a single, oval-shaped body segment where their cephalothorax and abdomen are broadly joined. They possess two eyes, often located on a raised turret-like structure. Unlike spiders, harvestmen do not produce silk or build webs, nor do they possess venom glands or fangs. Instead, they have chewing mouthparts that allow them to ingest solid food.
Conversely, cellar spiders, members of the family Pholcidae, are true spiders. They exhibit two distinct body segments, with a noticeable “waist” separating their cephalothorax and abdomen. Cellar spiders typically have eight eyes, often arranged in two groups of three, with two additional median eyes. They are known for spinning loose, messy, irregular webs, typically found in corners. As true spiders, they possess fangs and venom, which they use to subdue prey.
Activity Patterns of Harvestmen
Harvestmen are primarily nocturnal, though some species may also be active during daylight hours. Their activity is significantly influenced by light intensity, with a decrease in light at dusk signaling the onset of their active period. They often become more active on warmer nights. With generally poor vision, harvestmen rely on their long second pair of legs, which function as feelers, to navigate their environment and locate food in the dark. During their active periods, they forage for organic materials, and when not active, they typically rest in sheltered locations such as under logs or on tree trunks during the day.
Activity Patterns of Cellar Spiders
Cellar spiders, while often observed in their webs throughout the day, conduct hunting and web-building activities at night, constructing loose, tangled webs in sheltered corners. These spiders are highly sensitive to vibrations in their webs, which alert them to the presence of prey. Once an insect or other small invertebrate touches the web, the cellar spider quickly moves to capture it, biting and then wrapping the prey in silk. Some cellar spiders are also known to invade the webs of other spider species, consuming the resident spider, its eggs, or its captured prey. When disturbed, cellar spiders may rapidly vibrate within their webs.
Habitat and Diet
Harvestmen are frequently found in damp, dark places such as leaf litter, under rocks and logs, on the bark of trees, and within caves. Their diet is diverse; they are omnivores and scavengers, consuming small insects like aphids, decaying organic matter, fungi, plant material, and even bird droppings and feces.
Cellar spiders typically reside in human-habituated areas like basements, attics, sheds, and garages, as well as natural dark and damp recesses such as caves and rock piles. As predators, their diet primarily consists of insects and other spiders, including larger house spiders, redbacks, and huntsmen.