Ability to tell day and night.

[Pepper]

This is kind of a general question, but it involves a few reptiles or, activity times I should say..

Leopard Gecko, nocturnal: How do they know if it is day or night? Do they tell by coming outside of their hide and seeing that it's light, or by temperature if it drops at night?

Same with Crested Gecko's they are nocturnal, do they just peek out when it is light and stay hidden, and see when it's dark and come out?

Diurnal reptiles, like my fire skink: This is a weird question, because they stay buried for the night, how do they tell if it's day or night? Heat? They peak out to see if it's day time and time to forage for food?

It seems all three of my critters know what they are doing, the leo comes out periodically during the day, maybe to eliminate or change to the cool side for a few minutes, and then goes back in his side to sleep away the day.

The Crested stays hidden in his leaves or resting on his branches during the day, and at night ventures to the ground to eat his Crested Gecko Diet.

The Fire skink has been sleeping at night, and today he came out during the afternoon, ate some meal worms, and went back and buried himself.

But...how do they know?! Obviously people wake up after a certain time of sleeping, do they know, when they wake up it will be daytime/nighttime?

Thanks for any responses!

 

[Bodon]

i really think its the lighting to be honest. My cresteds wont come out if the light is on even if its hours after it gets dark out. Sometimes i forget to turn it off for them and i feel bad but mins. after i do they are out and about.

My tree frog, on the other hand, comes out at the same time every night, dark in the room or not, but if its light out he will sit around with his eyes closed. My leo will come and go no matter what the time is or what the light is like.

 

[Snowy & Petra de Gecko]

Well

I would have to say that it would depend on the lighting and the heat.

Other than that it would be the activity in the house.

 

[Libby15]

When I turn on his lamp in the morning, 95% of the time he is looking towards the window near his tank staring between the blinds and the light. I usually turn his light on when the sun is coming up.