Daddy Longlegs Risk Life... and Especially Limb... to Survive | Deep Look

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When predators attack, daddy longlegs deliberately release their limbs to escape. They can drop up to three and still get by just fine.

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We all know it’s not nice to pull the legs off of bugs.

Daddy longlegs don’t wait for that to happen. These arachnids, related to spiders, drop them deliberately. A gentle pinch is enough to trigger an internal system that discharges the leg. Whether it hurts is up for debate, but most scientists think not, given the automatic nature of the defense mechanism.

It’s called autotomy, the voluntary release of a body part.

Two of their appendages have evolved into feelers, which leaves the other six legs for locomotion. Daddy longlegs share this trait with insects, and have what scientists call the “alternate tripod gate,” where three legs touch the ground at any given point.

That elegant stride is initially hard-hit by the loss of a leg. In the daddy longlegs’ case, the lost leg doesn’t grow back.

But they persevere: A daddy longlegs that is one, two, or even three legs short can recover a surprising degree of mobility by learning to walk differently. And given time, the daddy longlegs can regain much of its initial mobility on fewer legs.

Once these adaptations are better understood, they may have applications in the fields of robotics and prosthetic design.

--- Are daddy longlegs a type of spider?

No, though they are arachnids, as spiders are. Daddy longlegs are more closely related to scorpions.

--- How can I tell a daddy longlegs from a spider?

Daddy longlegs have one body segment (like a pea), while spiders have two (like a peanut). Also, you won’t find a daddy longlegs in a web, since they don’t make silk.

--- Can a daddy longlegs bite can kill you?

Daddy longlegs are not venomous. And despite what you’ve heard about their mouths being too small, they could bite you, but they prefer fruit.

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