Harmless Daddy Long Legs Aren't Spiders At All

More than 6,000 species of daddy long legs exist in the world, with 235 in North America and 19 species right here in Illinois.

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Daddy long legs are very, very, very old. The oldest fossil ever found of one is more than 410 million years old! Despite how long they have lived on Earth, there are still many things about them that are a mystery to scientists. Here are some fun facts we do know.


Not a Spider


Daddy long legs, sometimes called harvestmen, belong to the group of animals called arachnids. Arachnids are eight-legged critters, and there are five main groups: mites, ticks, scorpions, spiders and daddy long legs. Daddy long legs are more closely related to ticks and scorpions than they are to spiders.


Here are a few main differences between daddy long legs and spiders:

One species of spider called a cellar spider looks a lot like daddy long legs, so much so that daddy long legs is another common name for this species. But if you look closely at a cellar spider, it is easy to recognize the two body parts, clearly showing it is a spider and not a true daddy long leg.


Adaptations, Diet and Life Cycle


Daddy long legs use their legs for walking, catching prey, smelling and breathing. Their second pair of legs is longer than the rest. They use these legs like an insect uses its antennae. If you observe one long enough, you may notice they use the mouth parts, called chelicerae, to clean their legs often.

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Daddy long legs have varied diets. They prey on pillbugs (what you may call roly-polys), mites, small insects and tiny eggs. They scavenge on dead worms, spiders and insects. Plus they can eat small particles of plants, fungus, fruit, sap and sometimes even bird droppings.


Females can lay up to several hundred eggs at a time in decaying logs or moss. The babies are tiny versions of their adult form. They molt about every 10 days, becoming adults in about one year. Males usually die soon after reaching adulthood, but females may live up to three years. One species found only in Brazil lives up to seven years!


Their Best Defense


Lizards, frogs and birds like to snack on daddy long legs, but there are several ways they can protect themselves. First, daddy long legs spend more of their day hiding than crawling around. When they do head out, they are experts at camouflage, blending well into their environment.

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Just like skunks, most species have scent glands that release an unpleasant odor, sending potential predators running the other way. If daddy long legs are really in a jam, they can “release” a leg, and it will continue twitching for a while, giving them an opportunity to run away. This is a last option because their legs do not grow back. If it is one of the more sensitive longer pairs, they will not survive without it for long.


Daddy long legs are completely harmless to humans, and they are fun to watch! Now that you are informed you can share your new knowledge with anyone who sees one and screams, “Spider!”