In some special case, some animals are hard to be recognized without the texture, such as zeebra, tiger and penguin. Especially penguin, its body shape is much stronger than the head. However, I would like to standalized all of them, except those small species animal, insect. Therefore, I have used the line to create the positive and negative in order to fit in with the idea.

About the facilities icon, our group have been suggested to use the 'one line' idea as well. Nonetheless, the result doesn't show that it is work. Since once inverting them, it shows that the shape and the thickness is too weak to indicate.