My Crested Gecko is staying on the bottom a lot?

I just got my crested gecko today, s/he has already eaten some of her CGD. But i've noticed that s/he stays on the bottom a lot, she rarely goes up to the top, I have an Exo-Terra 18 x 18 x 24" Terrarium with lots of Foliage and a large branch for her to climb on. I also have a Boston Fern made my Exo-Terra and she seems to stay on that quite a bit, but i never see her up in the trees, i thought maybe it was because I her daytime bulb on so she was hiding, but i just turned all of the animals lights off and she is still underneath the Boston fern, is something wrong?