Do hermit crabs prefer light of dark?

Question

Should I keep a light on at night or keep it light in the day and dark at night? By the way, they are in my room.

Answer 1

dark, I used to keep a heat light that is dark spectrum of light on at night, they come out in the night, and like the heat.

Answer 2

i would assume since they live on the bottom of the ocean they like the dark

Answer 3

they are more active in the night

Answer 4

I am a seasoned expert with land hermit crabs. Sadly, mine have passed on after a 2 year spell, dear little Castro, Shay and Fidel... I have found that they become a lot more active when the lights are off, however, I would suggest keep the light on in the day, and turn it off at night, around 9.00 p.m. This is just so as to simulate day and night and so that they don't get dehydrated with too much light exposure. Hermit crabs are a mystery though, the can and so often do die of unknown causes. It's devastating to see them in such a sorry state...