Fort building. That's not really a habit, but I did it a lot. I lived on a farm until I was 18, so there were [i]tons[/i] of places to do it. Until I was 10 or so, 1/2 of our house was unlivable. The floors were rotting and there was no electricity, so we lived in the half that was modernized and in good condition. That was awesome for me, because my friends and I had half a house to ourselves. We'd bring chairs and tables back there, tvs, etc, and play Pokemon. We didn't really [i]build[/i] it, but it was an awesome fort nonetheless. I also built a really shitty tree house out near the horse pasture. It had no walls or roof, just a floor that was kept up there by baling twine. And there was another one -probably my favorite- that was in our storage room. It was totally concealed beneath old mattresses, boxes, and furniture. Noone would have known it was there if I didn't tell them. The entrance was a long box that you opened and crawled down. Inside was an open area with my TV, Ps2, and N64. Oh god, it was amazing. Other forts included hollowed out piles of hay bales, swampy groves, etc, but those weren't as cool.