Most people think of granddaddy longlegs (GDLL) as spiders. They aren’t actually spiders, but they do belong to the Opiliones family of the arachnid family. They are closely related to mites and ticks. There are more than 6,000 species of granddaddy longlegs. There has been a myth going around that granddaddy longlegs are the most poisonous spiders, but cannot bite you because their mouth parts are too small. The fact is they don’t have any venom because they aren’t spiders.
The correct name for granddaddy longlegs is harvestmen. Harvestmen eat dead and decaying plants and animals. If you have lots of trees around your house, you will probably see lots of harvestmen around your windows and doors and in the fallen leaves.
Granddaddy longlegs have only two eyes and spiders have eight eyes. The body of a harvestman is different than that of a spider. Spiders have a head and a thorax. You can see the head and thorax as two parts. A harvestman only has one body part where the head and thorax is fused together.
Granddaddy longlegs should not be feared, because they aren’t spiders and they won’t hurt you. They serve a definite purpose in our ecosystem. They are scavengers and clean up rotting debris.
Granddaddy longlegs are not all males. They are called grand-daddy’s even most of the ones you see are female. The male and female harvestmen mate body to body. The male harvestman has a penis. The female harvestman has a vagina type opening called an ovipositor and the male has a penis called a gonophores. The male harvestman delivers sperm in the form of a spermatopore. They actually have sex and then the female lays eggs.
Since harvestmen are scavengers they eat bird dung, and fecal material from other animals. They eat fungi and many types of plant material. Some types of harvestmen hunt for live prey and will even ambush their prey. Harvestmen only have two eyes, so they don’t rely only on sight to find their food and to escape danger. They also use their second set of legs for antennae.
Another difference between spiders and harvestmen is that spiders have venom and inject their prey to immobilize them, and capture the prey in a web. A spider will eat by liquefying their meal. Granddaddy longlegs aren’t able to eat the same way that a spider does because they have no sucking apparatus in their bodies. They actually eat minute particles of animal and plant debris.
If you are scared of spiders, you can now differentiate a granddaddy longleg from an actual spider. There is no need to fear harvestmen and they are good for our environment. It’s best not to threaten a granddaddy longleg, because many species of harvestmen have a defense mechanism which causes them to emit a terrible odor to discourage a predator from killing it. If you see them, just let them alone because they are a valuable part of our ecosystem.