it was easy for the animals to work together. They had faith in each other's abilities and trusted that each would do the best according to his or her talents. It is for this reason that it became easy to trust the pigs and allow them to take over the leadership of the farm. The pigs, being the cleverest of all the animals, were entrusted with the duty of supervising and planning all the other animals' activities. Although they did not perform any physical labor, they were trusted unreservedly and their decision-making was respected. 

It is ironic, however, that the general animal populace's trust in the pigs would later have a negative outcome. This trust, and the pigs' superiority, would lead to them claiming privileges not offered to the other animals. This was foreshadowed by the disappearance of the nine buckets of milk and the windfall apples which the pigs later claimed was brain food which would ensure the proper running of the farm and prevent Jones' return. 

In addition, Napoleon got rid of Snowball and, through a ruthless purge, executed all the other animals who later confessed to having secretly assisted Snowball after his expulsion in his attempts to overthrow the farm. These acts gave Napoleon almost unlimited power and he became a tyrant, ruling through fear and propaganda. The animals were, then, in an even worse situation than they had been under Jones' rule.

Although the situation on the farm had taken such a dramatic turn, the animals still worked extremely hard and hardly ever complained. They were constantly tired, hungry and miserable but slaved away anyway. Their resolve to work together is most aptly illustrated by the building of the windmill. The work was hard and tedious, but they pushed on. Boxer became a symbol of strength and dedication, epitomized by his slogan, 'I will work harder.'

The animals were driven to work together because they believed that, even though life was tough, they were masters of their own destiny and were not being exploited by some selfish, greedy human. They were, therefore, prepared to make the sacrifices which, they believed, were in the interests of all concerned. The pigs' contribution still consisted of managing the farm by filling in forms and supervising, as it had been from the outset. At the same time, the pigs lived lives of luxury, having moved into the house, wearing clothes and adopting human characteristics and behaviour.

This state of affairs reached its climax when Boxer, the most loyal and dedicated of all the animals, was sent to his doom when the pigs sold him to the knacker when he fell ill. This was a ruthlessly cynical act and the animals were led to believe that the poor workhorse had died peacefully and had whispered in his last message that the animals should move forward in the name of the Rebellion and that 'Napoleon is always right." Even after this horrendously brutal act, the general animal populace still worked together, as hard as ever.

In the final analysis then, it was, at this stage the animals' gullibility, their fear for Napoleon and his dogs, the constant propaganda, lies and deceit and their belief in a greater good, that virtually compelled the animals to work together and all for what? So that the pigs could sustain their lives of privilege and behave, ironically, even worse than their previous oppressive master and his men had done. In the end, they could not even distinguish pig from human. 

Animals continue to work together throughout the novel, at moments building up real solidarity, such as when Boxer dies and is sent off.  Cats and rats do not get along, however, and at one point Mollie leaves because the others resent her bourgeois vanity. Significantly, Snowball is forced to leave by Napoleon because he disagrees with him. Following this, Napoleon makes Snowball the scapegoat for all the bad things that transpire on the far. They get along because they have subscribed to the idelogogy of "animalism," because they know the consequences of questioning (the dogs will attack them), and because they become so tired they do not have the energy to protest, because they cannot read or write and are easily persuaded by Squealer, and because they remain hungry as the story progresses, losing any energy for struggle.

Actually, all the animals on the farm (except for the pigs) work very well together.  There is no real complaining and no fighting as they plant and harvest and build (and re-build) the windmill.  The only trouble comes from the pigs and dogs who are lazy and threatening, respectively.  This pattern carries on for years--the animals working together, the pigs living off the fat of the land, so to speak, and the dogs intimidating any dissenters.  Eventually, of course, the animals start to figure things out and kind of "wise up."  We're left hoping they'll work together one last time--to overthrow Napoleon and their pig oppressors. 

I reworded the question because the original form did not make sense to me.  I tried to maintain what I perceived to be its intent and if I did not, I apologize.

I think that clearly demonstrates that the way in which the animals speak to one another and act towards one another is important.  For Orwell, this is a reflection of both personal expression and political reality.  For example, Old Major stands on a podium and speaks to the animals in an authoritative and yet almost aloof stature.  This is reflective of Animalism being a theory and Old Major simply wishing to articulate it.  In the early stages, Napoleon does not really speak to any of the animals with endearment and sense of camaraderie. His actions towards the other animals are driven by power and control, such as when he takes the puppies for his secret police and in his elimination of "Comrade" at the end of the novel.  His desire to remain separate from the animals in his own quarters and with his banning of weekly meetings also reflects such distance.  Using Squealer as his primary force of deception, Napoleon's speech and actions regarding the other animals represents distance, a desire for control, and a view of the animals as objects as opposed to subjects.

In contrast, Snowball networks with the other animals, speaking to them in direct terms and in speech that is directly impacting their being.  Snowball speaks with the presence of the Revolution in his interactions with the other animals, seeking to make committees, and ensure that as many animals as possible have a voice of understanding in the political system.  Clover speaks to the other animals with a sense of maternal guidance, such as how she tries to bring Mollie back and the confusion she experiences after seeing Napoleon kill so many animals in the public executions.  Boxer seeks only to help and not to harm "not even a human life."  Both Boxer and Clover represent how there can be a sense of goodness and decency even when it is noticeably absent in social settings.  The goodness that these characters display might be a reason why they lack power in the final analysis.  Orwell might be saying that modern political structures are predicated upon those in the position of power who are fairly cruel in how they interact with others, justifying the need for public vigilance in securing their removal from power.