Bat drawing

My class on Bestiary drawing at the Observatory gallery in the Gowanus section of Brooklyn finished a few weeks ago. It was a great class, taught by Saul Chernick.
This is my completed drawing of a bat. One complication I had was that I worked on the drawing with the bat right side up but I really wanted to display her upside down. However, I just could not get the composition to work that way. So I changed her 'thumbs' to allow her to be hanging right side up. A little odd, since it means she is holding on by both hands and feet. But new mother's are often overly cautious.