Okay, now I want to share one of my projects that I did, my hideout that I made. I am very proud of this project, it is a mountain with a cave. Basically what I did was made the basic structure of it out of a cut out tissue box, a Chinese take out bowl, and wire. After that I used the magical Great Stuff insulating foam. I covered the basic structure with the foam and let it dry, and it expanded so much! Here is the picture after I used the foam and let it dry.

Next I used a serrated knife to carve it to the shape I wanted.

Then I added some acrylic paint to paint the carved foam.

And lastly I stuck some fake plants in the foam, and glued some rocks to the mountain. And here is the finished product.

And here is a picture of my lovely Ollie chilling in the cave part.

My crabs love climbing on it, hiding in the pants, and hiding in the cave. And I have an opening against the side of the glass that allows me to look in and see who is hiding! But, unfortunately, yesterday, I caught Ollie picking and eating at the foam. But it could have been because she was stuck, so I moved her and cut off the part she was eating, and I'm hoping she doesn't eat any more.
I hope you guys like it, and that it may inspire or help you with any ideas for making your own hideout!