A brain chemical tells when to fight or flee
Nitric oxide turns off urge to fight, making battered crickets flee a face-off
![cricket](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2015/03/kb_cricket_free.jpg?fit=860%2C460&ssl=1)
BRAWL OR BOLT A Mediterranean field cricket depends on its nerve cells to release nitric oxide to help it decide when it’s beat in a fight and needs to flee.
Paul A. Stevenson, Jan Rillich