P9

In the wild, animals face daily challenges for survival, constantly seeking food while avoiding predators.  Some animals have discovered that cooperating with others eases these struggles. This type of mutually beneficial relationship is called symbiosis. 

One striking example of symbiosis involves the formidable African crocodile and the tiny plover bird. When a plover is present, a crocodile opens its large, sharp-toothed jaws, seemingly inviting the bird inside.  Surprisingly, the plover accepts this invitation, and even more astonishingly, the usually aggressive crocodile doesn't close its jaws and consume the plover. Instead, it remains motionless until the bird leaves. The explanation lies in symbiosis. The plover diligently picks out tiny pieces of meat lodged between the crocodile's teeth, effectively cleaning them and preventing infections.  As the crocodile is unable to clean its own teeth, it relies on the plover for this service. In return, the crocodile offers the plover an easy meal.