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.
For more science reporting and stories, follow Nell on twitter @nell_sci_NPR. And, as always, email us at [email protected]
This episode was produced by Thomas Lu, edited by Gisele Grayson, and fact-checked by Ariela Zebede.