KINGDOM: Animalia | PHYLUM: Arthropoda | CLASS: Arachnida | ORDER: Opiliones (harvestmen)

Other Names: daddy-long-legs, opilionids, shepherd spiders, granddaddy-long-legs, reapers

Harvestmen are members of the class Arachnida, which also includes spiders, scorpions, and mites.  Like all arachnids, harvestmen have 4 pairs of legs, fang-like mouthparts called "chelicerae," and 2 antennae-like appendages near the mouth called "pedipalps."  They have no antennae.  Most Kentucky harvestmen have very long legs, and these species are usually called "daddy-long-legs."  Some harvestmen have short legs and look very similar to mites, but these species are rarely seen in Kentucky.  

Harvestmen are often confused with spiders, but harvestmen are not true spiders.  Spiders have 2 body segments (cephalothorax and abdomen) that are distinct and separated.  On harvestmen the 2 body segments appear fused into a single large body segment (as with mites and ticks).  Also, spiders have venomous fangs, whereas the fangs of harvestmen have no venom glands.

Like all arachnids, harvestmen have incomplete metamorphosis.  This means that young harvestmen hatch from eggs and look like tiny versions of the adults. They molt (shed their skin) as they grow larger.  Most harvestmen in Kentucky live for about a year.  Females lay eggs by the hundreds in moist soil.

The biology and ecology of harvestmen is poorly known.  Most harvestmen species are found in moist, shady environments.  Some harvestmen live deep in caves, while others are found in basements or in the deep shade of woods or plant growth.  Regardless of where they live, they are usually active in darkness or in the shade.  Some harvestmen search methodically over the ground and on plants for slow-moving or dead insects, insect eggs, earthworms, and decaying plant material.  Harvestmen are often seen sitting motionless on the upper sides of leaves, like the one shown below, perhaps waiting in ambush for soft-bodied insect prey.

Harvestman on leaves (B. Newton 2003)

Although they resemble spiders, harvestmen do not have venomous fangs or silk glands.  Some species, however, have glands on the sides of their bodies that can secrete bad-tasting and bad-smelling defensive chemicals which help protect them from predators.  Harvestmen are sometimes eaten by birds, large spiders, and predatory insects like assassin bugs.

Harvestmen are often found with bright red mites attached to their bodies.  These mites are the immature stages of species belonging to the family Erythraeidae.  They are believed to be parasitic.  Among many mite species, the immature stages are parasitic while the adults are predatory.  A "parasitic" organism is one that attaches itself to and feeds on a host, like a tick on a human.

DADDY-LONG-LEGS: Leiobunum genus
FAMILY: Leiobunidae | Genus: Leiobunum

During warm months, harvestmen are extremely common on the shady sides of buildings, underneath eaves, in crawl spaces, and on trees, and they are found in both rural and urban environments.  Harvestmen can be easily collected by hand, but take care not to break off any legs.  Harvestmen will usually stay still for a photo as long as you don't touch them.  These creatures have soft bodies, and should be preserved in alcohol.

The legs of harvestmen fall off easily and continue to twitch for some time after removal.  It is believed that this helps the daddy-long-legs escape predators (as when a lizard's tail breaks off).

You may have heard that "daddy-long-legs are the most poisonous spiders in the world, but their fangs are too small to bite humans."  This is a widespread myth.  It has even been presented as a fact on televised nature programs.  Daddy-long-legs are not actually spiders, and they do not have venom glands.  For details about this myth, take a look at this webpage from the University of California Entomology Department.

In the old days, it was believed that you could use daddy-long-legs to find your lost cattle.  When you wanted to know which direction the herd had wandered to, you could pick up a daddy-long-legs by all of the legs but one, and the free leg would point in the direction of the cattle (or so it was believed).

Another myth from the old days: if you kill a daddy-long-legs, it will rain the next day.