The other thing I've noticed is that this is good practice for me in really getting down to the essence of my subject. I'm trying to make all of the animals and plants (and fungi) as realistic as possible, but they're so small I have to do it with just a few lines. So far, I'm pleased with them. This is my favorite - Bullfrog:
The others - D (a newer version), E, H, O and X - can be seen in this Flickr Photoset.