Rectangular pupils are a feature of some grazing animals, but not all.
Here's why:
* Rectangular pupils are an adaptation for panoramic vision. This allows animals to see a wider field of view, which is helpful for spotting predators approaching from different directions.
* Grazing animals often have large fields of view, but not all of them have rectangular pupils. For example, sheep and goats have round pupils.
* Other animals, like some fish, reptiles, and amphibians, can also have rectangular pupils. This is because they also benefit from the wide field of view that this shape provides.
Therefore, it's not accurate to say that all grazing animals have rectangular pupils. This is a specific adaptation that is found in some, but not all, grazing animals.