My female is laying her first clutch of infertile eggs right now. I should turn off her lights at nighttime as usual, right? Or can she not see without them? I have no clue if I should or not....
She wont pat down the sand and dirt in the same way a human would (of course). The best way to know that it wont collapse is just by testing the mixture with your fingers. If it holds well, it should be okay. I tend to add more sand just for extra support. Make sure there is enough moisture as well in the mixture. That will help her make a tunnel as well as hold it up.
They don't pack the dirt to make a tunnel, they dig. And yes, they pack the substrate exactly like a person with three thumbs and two fingers would to fill it in. The soil/sand mixture will actually hold a more stable hole if packed slightly and properly moistened. Remember, they naturally dig into the root balls of plants in the wild. Either way, keep the natural circadian cycle as zlew mentioned.