Daddy Longlegs: Spiders & Other Critters

daddy-long-legs-02 — A group of daddy long-legs of the order Opiliones.

(Image credit: Creative Commons | Luis Fernández García)

Daddy longlegs is a term used to refer to three different types of critters, and only one of them is a spider. A common belief is that daddy longlegs spiders are the most venomous spiders in the world. However, that is an urban myth.

Harvestmen & crane flies

The term “daddy longlegs” most properly refers to an arachnid in the order Opiliones, which are also called harvestmen, according to the department of entomology, soils, and plant science at Clemson University. This outdoor arachnid typically lives under logs or rocks. Unlike spiders, it has only one pill-like body segment. It also has only two eyes, does not spin webs, and is not venomous. Wisconsin Natural Resources magazine wrote that, like the spider, it has eight very long legs that can be 30 times as long as its body.

These daddy longlegs have two body segments — a cephalothorax and an unsegmented abdomen. Jo-Anne Nina Sewlal, an arachnologist at the University of the West Indies in Trinidad, described the abdomen as “very prominent” and “either round or oval shaped.” Like other spiders, these daddy longlegs have eight eyes, which Sewlal said are “arranged into a central pair and two clusters of three on either side of this pair.”

Daddy longlegs spiders range in color from cream to brown or gray, and according to SF Bay Wildlife, some species have brown stripes on the ventral side of their body. The daddy longlegs’ characteristic long, skinny legs are several times the length of its small body. Daddy longlegs spiders can range from 2 to 10 mm long, but their legs can grow up to 50 mm according to the entomology department at Pennsylvania State University. The female is slightly bigger than the male.

Daddy longlegs spiders live on every continent except Antarctica. They prefer damp climates but can nevertheless thrive in deserts. According to the department of entomology at the University of Kentucky, they are especially successful in urban areas where they spin thin, tangled webs in ceiling corners, under furniture, in garages, barns, attics, and basements, and other places where they’re unlikely to be disturbed. Daddy longlegs may be useful spiders because they can help keep the population of other insects and spiders down, according to the Queensland Museum.

Sewlal described two fascinating defense mechanisms of daddy longlegs spiders. She said that some neotropical species engage in an action called “whirling.” She described it as when “the spider holds onto the underside of its web and swings its body in horizontal circles until it looks like a blur to the human eye. This is a defense mechanism and serves to make the spider appear bigger than it really is. This is particularly useful since they have visual predators such as birds, lizards and even other spiders like some species of jumping spiders.

Daddy longlegs spiders can mate throughout the year. According to the Natural History Museum of Los Angeles County, like most spiders, the male squirts sperm onto the web then sucks it up into his pedipalps, a pair of sensory appendages near the mouth. It then inserts the pedipalps into the female’s epigynum (external genital opening), and she carries the sperm around with her until she lays her eggs.

According to Clemson University, daddy longlegs spiders carry their egg sacs in their jaws at all times — with the exception of eating — until the eggs hatch. Then, the newly hatched babies crawl onto the mother’s body for a brief stretch of time. It takes about a year for the baby spiders to develop from egg to adult. Male daddy longlegs typically live for about one year and die after mating. Females can live for three years.

According to urban legend, daddy longlegs are the most venomous spiders in the world, but their fangs are too weak to penetrate human skin. However, this myth was busted on the Discovery Channel show "Mythbusters." A daddy longlegs spider was coaxed into biting the arm of the show's co-host, Adam Savage. He reported nothing more than a very mild burning sensation from the spider's venom that lasted just a few seconds.

Jessie Szalay is a contributing writer to FSR Magazine. Prior to writing for Live Science, she was an editor at Living Social. She holds an MFA in nonfiction writing from George Mason University and a bachelor's degree in sociology from Kenyon College.

Daddy Longlegs: Spiders & Other Critters

Harvestmen & crane flies

Cellar spiders

Daddy longlegs spider habits

Mating

Venom myth busted

Taxonomy/classification