When a small herd of cows, with calves, is properly threatened, it may form a circle. Each cow facing outward, with the calves in the middle, protect by the herd. I have seen this done, when a herd of about a dozen herefords, with several calves, was threatened by several dogs.
The circle was amazing. Consider the complex decision making and group coordination required to execute this behavior.
First the herd has to collectively decide that the proper threat exists. How this is done is of course a deep mystery.
Then they have to form up into a good circle. This is far more sophisticated that simple grazing together. The Roman battle square comes to mind. How does each cow decide where to go, or who to get next to?
To see the complexity, consider this question. If you had a dozen robotic cows, how would you program them to quickly form a good cow circle? This is clearly a grand challenge. Until this question can be answered I would say that we do not understand the behavior.
Then the calves have to get into the center. A cattleman friend tells me that there is a call that mother cows can make that brings their calf running. Perhaps this plays a role in the protective circle behavior. There may even be a specific "get into the center" call. While perhaps not language it would certainly be auditory communication. (The crows seem to do a great deal of this.)
Then when the threat has passed, as it did when I chased the dogs away, they have to collectively decide that it has passed and go back to grazing.
Instinct tells them how to do all this, but the decision making still has to be done in each specific instance. The cow circle is an amazing case of collective action.