Just another dumb question

[trainfever]

I was in the hobby about 20 years ago and just get back into it recently. I bought my first starfish ever last week. It is doing fine. It is a small Serpent star. Its disk is about an inch in diameter with its arms extending out about 2 1/2 inches long.
I noticed that when I have the lights off in the tank, the starfish comes out into the open, but as soon as I turn the tank lights on, he crawls under a rock somewhere and hides. I read that starfish are nocturnal and come out at night to hunt for food and hide under rocks during the day.
Now my dumb question: If a starfish has no eyes, how can he tell when it is night time? :thinking: :notsure:

 

[wax32]

Eyes aren't the only light detecting organs that creatures can have.

 

[sankysyuck]

Some species of starfish actually do have eyes, there just not detectable, there usually at the end of there arms close to there tube feet. And like was said before, there are other ways of telling whether it's safe or not to come out.