you don't
if your fish is going around the tank with its eyes cosed multiple times.
fish dont actually sleep; they have no eyelids. scientists dont know for sure but they think that they go into a state of rest. It can be hard to tell if a fish is sleeping; they might float motionless, float on bottom of tank or hide in tank decor.
To determine if your fish is sleeping or dead, observe its breathing and movement. If the fish is still breathing and shows some movement, it is likely sleeping. However, if there is no movement and the fish is not breathing, it may be dead.
Sadly, Florida Beach does not protect fish from dying. Fish die everywhere. You know what, it's sleeping honey, don't poke it. The seagulls are kissing it.
It can be difficult to tell if a fish is sleeping or dying. Look for signs of movement or breathing to determine if the fish is still alive. If you are concerned, consult a veterinarian or a fish expert for advice.
a fish sleeps with its eyes open...so you cannot notice whether its awake or sleeping..or even if it sleeps...it stays in one place
They eat you when your'e sleeping >:)
http://www.fact4dummies.com/animal-facts/fish-make-sleeping-bag
fish dont have eyelids
Maybe their sleeping or they are dead.
Well, you could touch him, but that's not reccomended. Most likely your fish it dead, or sleeping. I've never heard of a fish playing dead.
If it is under its shell its sleeping