Potter either had no live models for the eastern chipmunk characters, or borrowed a pet chipmunk from a cousin. Initially, she may have been unsure of how to draw the chipmunks and chose to clothe them, then was forced to follow suit and clothe the two main players as well, while leaving the other squirrels in their natural state. Or, she may have clothed Timmy and Goody because they collect their nuts in sacks (an unnatural way for squirrels to behave) in imitation of a ruse she employed in "Peter Rabbit" when Peter only walks on his hind legs while wearing his blue jacket. When he loses his jacket, he reverts to being an animal and moves about on all fours. Because Timmy and Chippy were not drawn from nature, the two suggest stuffed animals in their lack of engaging facial expressions.