The daddy long-legs is one of the most recognisable spiders. Sometimes called the cellar spider, granddaddy long-legs, daddy long-legger, harvestmen, vibrating spiders or house spiders, many people regard these arachnids as "good" or "helpful" spiders, but they aren't spiders at all. Scientifically these arachnids are opiliones. Daddy long-legs species live outdoors in shady areas and in houses and basements throughout the United States.
Usually grey or light brown in colour, the big-eyed daddy long-legs look somewhat flimsy. Two eyes are positioned on the daddy long-legs body. Its body is all one part, with its head and thorax fused together. Extra long legs give the daddy long-legs its name and a delicate, gangly appearance. When handled, the legs may fall off and even continue vibrating or twitching briefly.
Daddy long-legs build disorganised and tangled webs in nooks and crannies throughout the United States. According to Fox Pest Control, "The web is a tangle of irregular, soft strands which looks like a rough horizontal sheet about 25cm across." They hang upside-down for hours or even days in these dark, damp spaces. In nature, daddy long-legs prefer to build webs in caves, under rocks or loose bark and in abandoned animal burrows.
Harvestmen daddy long-legs, common to the United States, grow slowly. Newly hatched daddy long-legs are smaller versions of the adults, and must go through many moults before reaching adult size. Usually, a young daddy long-legs will be fully adult by summer. Adult males have bodies 1/4 inch long and their legs can be up to 2 inches long. Females' bodies generally range from 1/10 to 3/10 of an inch long. Adult daddy long-legs live up to a year, but die earlier in colder climates.
Daddy long-legs have a reputation of being good because of their habit of invading other spiders' webs. Harvestmen will eat spiders, insect eggs and any other soft insects. Sometimes, they vibrate on a spider's web to mimic a trapped insect and trick the spiders into coming out. In nature, the daddy long-legs hunts the Tegenaria species, redback spiders and huntsman spiders.
One common misconception is that daddy long-legs are poisonous to humans. You may have heard that "daddy-long-legs are poisonous spiders, but that their fangs are too small to bite human flesh. According to the University of Kentucky Entomology department, this widespread myth has even been presented as factual on televised nature shows. Since daddy-long-legs are not actually spiders, but opiliones, they do not have venom glands and so are not poisonous.