Question: How Newts Sleep?

Hi, I have not post in here for sometime. Anyway, today I have noticed something that I have never notice for the past years in newt keeping. I saw one of my Fuzhong Warty newts closed it's pair of eyes for a long time. This is the first time I have noticed this. I have not noticed such behavior with my cynops orientalis and my other two newts. After a while of observation I put my finger in the water next to the warty newt and it opened it's eyes.

I know that there are some documents regarding the sleep of different animals. Mammals probably work the same as humans, although the length of the sleep varies. Some animals have no physical capability to close the eye lids. However, does anyone know how this work for newts? Do you think my warty newt closing it's eyes is a sleeping behavior? Or a sign of stress? Or a sign of disease? (It is not the dominant newt among the three newts sharing the same tank with their own hideout.)

If they do sleep, how does it work? How long will that last? Anyone ever observed this?

It probably was sleeping. I've noticed this before in my newts.

I am still somewhat a Newt Newbie. I am constantly checkin on the and I have seen my two close they're eyes while sleeping a reasonable amount of time. I've done that same thing though! Reaching in to check up on em the first time I saw it! i think it is normal.

Thanks for the confirmation. It is interesting how I have never spotted a newt sleeping. I guess I have too many newts in one tank, having them all distracting each other's sleep.