These monkey tessellations are based on the equilateral triangle tile. The monkeys leave their regimented two dimensional existence, climb an octet structure and leap into the air spreading their arms in exultation. Then they return to their daily grind.
The octet structure they are playing on is made from alternating octahedra and tetrahedra bricks. Unlike conventional rectangular bricks, these have triangular faces.
I've hidden stuff in the painting's texture. Detail may be seen at [link]