When we got Lucy, we didn't crate her at first when we were at work. She, like many pugs, and other dogs, developed separation anxiety. This manifested in many ways, the most amusing however, can be seen in the picture below.
Twenty dollar pet bed from Wal-Mart - destroyed. So we began to crate her and haven't had many issues since. I mean, really, how can you get too mad at a face like this?