I am fascinated with the drawings of Escher ever since I saw  a large exhibition of his work in real life at the Pompidou Museum in PAris a few years ago .  
 I chose here  only  a couple of examples of  BIRDS and FISH.It was through his work I began looking at nature in a a different way . . .and discovered  TESSELLATIONS . .
I am going through my hooking sketch Journal this morning and came across these postcards from the TASCHEN publication . . .I will post more but here are a few to LOOK at today . . ..there is always so much to SEE in his work . . .what are tessellations?
Look at the bottom of page for the Wikipedia Encyclopedia  brief explanation. . . or GOOGLE:Tessellations!!!
From Wikipedia, the free encyclopedia
A Honeycomb is an example of a tessellated natural structure
A tessellation or tiling of the plane is a collection of plane figures that fills the plane with no overlaps and no gaps. One may also speak of tessellations of the parts of the plane or of other surfaces. Generalizations to higher dimensions are also possible. Tessellations frequently appeared in the art of M. C. Escher. Tessellations are seen throughout art history, from ancient architecture to modern art.