Nature loves a crowd.
These pictures all make the point that Nature teaches us to accommodate one another in a crowd. The middle picture of a Mexico city crowd doing the wave demonstrates simply that we are no different from ants, fish and countless other species when we come together in huge numbers. Clearly Nature normally absorbs crowds, but sometimes they become overwhelming. We call this plague. Consider the space occupied by the schooling humans in the middle picture with the physical space occupied by the creatures in the other two pictures.