Diorama

So I've been taking this class at the Y. I'm learning how to make museum dioramas! Here's my project.

I think the background painting is pretty good. I don't know, maybe it's too clean? Should I add a touch of...what? Poo? Trash? Air pollution? Something to mess it up, make it more real-looking?

The animals aren't quite right, I grant you that. I got the contours okay but their expressions are sorta stiff, not quite alive-looking. So yeah, I have to work on my taxidermy skills.

Suggestions?