REM sleep protects animals against predator attacks
Rapid eye movement (REM) sleep brings about brief but periodic awakenings. In 1966, Dr. Frederick Snyder reported the "sentinel" function of REM could help animals prepare a fight or flight response against potential predator attacks.
Neuronon Jan Emily Henderson Shenzhen Institute Of Advanced Technology Chinese Academy Of Sciences Shenzhen Institute Advanced Technology
Source: news-medical.net