I like it better this way. The black background makes the head of the snail appear almost translucent. Good contrast also helps to accomplish that task.
~~~~~ actualy it IS translucent ... i watched her munching some undefinable stuff.... muddy parts of a rotten leaf i guess, darkbrown ....i could actually see how this stuff moved bit by bit under her skin along her head ... her esophagus (right word? i had to look it up) must be positioned right under top of her head. was a strange expirience to actualy watch her inner boddy functions from outside. sorry to those for whom it might be a bit too much information ;) but this was rather interesting.
also check image Mvc-379fram "the little guys" album.