The different animals reveal their personalities as they enter the barn. Let’s start with Old Major, who’s already sitting in the barn when the scene begins.

1. Old Major sits in a comfortable way that shows he is calm, kind, dignified, and very much in charge:

Major was already ensconced on his bed of straw, under a lantern which hung from a beam. He was twelve years old and had lately grown rather stout, but he was still a majestic-looking pig, with a wise and benevolent appearance in spite of the fact that his tushes had never been cut.

2. The three dogs and the pigs come in first and sit down right in front of Old Major, which shows that they are prompt and obedient:

First came the three dogs, Bluebell, Jessie, and Pincher, and then the pigs, who settled down in the straw immediately in front of the platform.

3. The hens and pigeons come in and settle themselves in the places where they are most comfortable, showing that they are prompt and attentive, but perhaps less eager than the dogs and pigs:

The hens perched themselves on the window-sills, the pigeons fluttered up to the rafters…

4. The sheep and cows come stretch themselves out comfortably behind the pigs and chew their cud. This shows that, like the birds, they are perhaps ready to listen and follow orders, but perhaps they care a bit more about eating than doing so, and they aren’t quite as excited as the dogs or pigs:

… the sheep and cows lay down behind the pigs and began to chew the cud.

5. The horses come in as a pair, showing their friendship, and they sit down carefully so that they don’t hurt any of the tiny animals, showing their conscientious manners:

The two cart-horses, Boxer and Clover, came in together, walking very slowly and setting down their vast hairy hoofs with great care lest there should be some small animal concealed in the straw.

In particular, the narrator tells us directly that although the horse Boxer looks and is rather stupid, he’s actually very respected on the farm because of his good character and his hard work:

A white stripe down his nose gave him a somewhat stupid appearance, and in fact he was not of first-rate intelligence, but he was universally respected for his steadiness of character and tremendous powers of work.

6. Muriel, the goat, and Benjamin, the donkey come in next, and although we don’t see how they enter or where they sit, the narrator tells us directly that Benjamin has a bad attitude, that he’s very negative and serious, and that somehow he was still very good friends with Boxer:

Benjamin was the oldest animal on the farm, and the worst tempered. He seldom talked, and when he did, it was usually to make some cynical remark—for instance, he would say that God had given him a tail to keep the flies off, but that he would sooner have had no tail and no flies. Alone among the animals on the farm he never laughed. If asked why, he would say that he saw nothing to laugh at. Nevertheless, without openly admitting it, he was devoted to Boxer; the two of them usually spent their Sundays together in the small paddock beyond the orchard, grazing side by side and never speaking.

7. The ducklings wander in helplessly next, then get cozy and fall asleep, revealing how clueless and useless they are:

The two horses had just lain down when a brood of ducklings, which had lost their mother, filed into the barn, cheeping feebly and wandering from side to side to find some place where they would not be trodden on. Clover made a sort of wall round them with her great foreleg, and the ducklings nestled down inside it and promptly fell asleep.

8. Mollie, the mare, comes “mincing daintily in,” meaning she prances in, showing off. Right away she sits down in the front of the room and shows off her mane, which is decorated with fancy ribbons. She’s also enjoying a sugary treat. So, we can see that she’s self-indulgent, a show-off, someone who loves attention:

At the last moment Mollie, the foolish, pretty white mare who drew Mr. Jones’s trap, came mincing daintily in, chewing at a lump of sugar. She took a place near the front and began flirting her white mane, hoping to draw attention to the red ribbons it was plaited with.

9. The last animal to come in is the cat, whose name we aren’t told; she looks for a warm place to sleep and ignores absolutely everything being discussed. She purrs, enjoying herself. So, we know that she is utterly uninterested in what Old Major has to say, nor does she care much about the farm as a whole.

Last of all came the cat, who looked round, as usual, for the warmest place, and finally squeezed herself in between Boxer and Clover; there she purred contentedly throughout Major’s speech without listening to a word of what he was saying.

10. Finally, one animal didn’t enter the barn at all. Moses, the raven, instead remains sleeping outside of the barn, revealing his total indifference to the other farm animals:

All the animals were now present except Moses, the tame raven, who slept on a perch behind the back door.

The dogs and pigs enter the barn at once and claim front-row seats, as their status demands. It is, after all, a pig they have come to hear. The birds, in sharp contrast, have the humility to accept a seat on the periphery: hens on the windowsills and pigeons in the rafters. This immediately establishes an order of precedence among the animals which is reinforced by the sheep and cows settling themselves behind the pigs. Clover and Boxer come in very carefully, checking to ensure that they are not harming any other creatures with their big hooves, emphasizing their protective, gentle natures.

The ducklings are lost and vulnerable, entering in a vague and purposeless manner that befits their youth and inexperience. Clover shows her motherly nature by protecting them. Mollie, the white mare shows her rather feckless nature by leaving her entry to the last moment and chewing a lump of sugar as she comes in. Finally, the cat demonstrates a selfish obsession with comfort by failing to listen at all and instead focusing on finding the warmest place to sit—despite having come in last.

The way the animals come into the barn during the meeting does say a lot about them.  Old Major is lying on a bed of straw on a platform with a lantern lighting him.  This demonstrates both his age and his respected position among the animals.

The dogs come in first, which demonstrates their energy and eagerness.

The pigs come second, and they sit in the straw, right in front of the platform.  By doing this, they are putting themselves up to the standing of Old Major, associating themselves with him as his equal and sharing in his support.

The hens and pigeons both perch, on the windowsill and in the rafters, because they are always on the periphery of activity throughout the book.

The horses come in carefully and slowly, in case they might trample another animal.  This represents their strength and compassion, as does Clover creating a nest for the ducklings.  Mollie, on the other hand, is one of the last to enter and is more interested in her sugar and ribbons that the other animals or the meeting.  Muriel and Benjamin come in together, and throughout the story usually remain together.

The processional entrance of the animals hints at the hiearchy which is to follow. The dogs first march in, escorting the pigs following close behind:

At one end of the big barn, on a sort of raised platform, Major was already ensconced on his bed of straw, under a lantern which hung from a beam. He was twelve years old and had lately grown rather stout, but he was still a majestic-looking pig, with a wise and benevolent appearance in spite of the fact that his tuskes had never been cut. Before long the other animals began to arrive and make themselves comfortable after their different fashions. First came the three dogs, Bluebell, Jessie, and Pitcher, and then the pigs who settled down in the straw immediately in front of the platform. The hens perched themselves on the window-sills, the pigeons fluttered up to the rafters, the sheep and cows lay down behind the pigs and began to chew the cud. The two cart-horses, Boxer and Clover, came in together, walking very slowly and setting down their vast hairy hoofs with great care lest there should be some small animal concealed in the straw....

The sheep and cows have secondary roles and the chickens and pigeons take their place among the rafters. When Clover the mare settles down next to her mate Boxer, she protects a brood a ducklings from her heavy hoof. Mollie the pony comes in fashionably late, evidently wanting to be noticed. The cat saunters in late too, looking for the most comfortable niche she can find. Moses the raven is not mentioned at all.

The scene with its pastoral charm portrays the farm animals united under duress, and a certain harmony and cohesion of the group is already evident. Old Major distinguishes himself as the leader, but it is also mentioned that Napoleon, an impressive pig simply because of his massive statue, is the only Berkshire boar on the farm. (Therefore, he is not of the offspring of Old Major but 'something else'!) Moreover, the authoritative roles of the pigs and dogs is also present and forebodes trouble to come.