It sticks very well but the hideout is way too small for created geckos! The entry hole is very narrow and I can't even fit any of my fingers in it except my pinky. It definitely isn't roomy in the hideout and my poor crested gecko can't even fit its entire body in it. She can fit only her head and some of her torso but not much to give her some elbow room. I wish this was a bit more roomier and the entry was a bit more opened up.
This sticks well to the side of an enclosure. Currently my baby crested gecko won't go in it but likes to sit on top of it. So, they are getting some use out of it. The second will be given to the baby spider when she gets a bit bigger.