How Animals and Insects Bleed To Defend Themselves : Short Wave Some insects and reptiles have a strange self-preservation characteristic — they suddenly start bleeding from places like their eyes or knees. NPR science correspondent Nell Greenfieldboyce looks at "reflex bleeding" and explores some of the creatures that bleed on purpose.

For more science reporting and stories, follow Nell on twitter @nell_sci_NPR. And, as always, email us at shortwave@npr.org.
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When Critters Bleed ... On Purpose!

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When Critters Bleed ... On Purpose!

When Critters Bleed ... On Purpose!

When Critters Bleed ... On Purpose!

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  • <iframe src="https://www.npr.org/player/embed/933533854/933587283" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
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Martin Ruegner/Getty Images
Lady bug on a stem
Martin Ruegner/Getty Images

Some insects and reptiles have a strange self-preservation characteristic — they suddenly start bleeding from places like their eyes or knees.

Scientist Sebastian Hoefer says, "It really does look like it's deliberate. Deliberately, it's bleeding to put this show on."

A show put on to deter any would-be predators. NPR science correspondent Nell Greenfieldboyce looks at "reflex bleeding" and explores some of the creatures that bleed on purpose.

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For more science reporting and stories, follow Nell on twitter @nell_sci_NPR. And, as always, email us at shortwave@npr.org.

This episode was produced by Thomas Lu, edited by Gisele Grayson, and fact-checked by Ariela Zebede.