What does the different ways in which the animals behave as they come into the barn during before Old Major's speech tell us about them? In Animal Farm

The way the
animals come into the barn during the meeting does say a lot about them. 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.