Originally I got the crate for Zenzy. However, Yukon took over the crate and used it as his sleeping spot. He just loves the crate and whenever he wants some alone time he is using the crate.
When we found Bones, we first kept him in the crate to protect him from the two monsters. I guess he figured the crate is his and took over.

I felt kind of bad for Yukon. He wanted to go and lay down when he found out Bones took his place.