Can fish sleep with their eyes open?
They are sleeping, and they can sleep at any time during the day or night. Fish do sleep with their eyes open, because they don't have eyelids (except for some sharks) to close! ... For fish, sleep is more like a resting period similar to a daydream that humans might experience.
Join Alexa Answers
Help make Alexa smarter and share your knowledge with the worldLEARN MORE