Both Snowball and Napoleon have interactions with the animals. The strongest example of this can be seen in the third section of the book. Once power has been consolidated in the hands of the pigs, Snowball sets to the task of organizing the farm's activities in the form of committees and groupings that will maximize efficiency on the farm. Snowball also directly interacted with the animals to make sure they understood that what was being done was in line with the revolution's goals and aims. Snowball's interaction with the animals was one predicated upon the revolution and assuming his role as what Marx would have called, "the vanguard of the proletariat." Snowball loved the revolution and his interactions with the animals were based off of this idea.
This was not the case with Napoleon, who "took no interest in Snowball's committees." Instead, he argued that "the education of the young" was the most important and takes nine puppies from Jessie and Bluebell and isolates them along with himself, training them and working with them. They will eventually end up forming the secret police that will insulate Napoleon from the other animals, provide protection for him and enforcement for his policies against opposition and dissent. For Napoleon, his interactions with the animals is predicated upon the notion of power and the distance that comes with it.
Orwell states time and time again that Napoleon "was not one for speeches." This reflects how he interacted with the animals on the basis of power and authority. Snowball loved making speeches and enjoyed interacting with the animals on the basis of the revolution. It is here where a fundamental theme from the work is evident in that it is one thing to declare independence and another to keep it. Snowball's interactions with the animals represents the former and Napoleon's interactions with them represents the latter.