Animal people are probably the most neglected things in DF. For being around for forever, they are incredibly shallow. I'd love for them to get more attention.
Well, I was thinking that animal people should create societies that are more or less based on the actual animal societies that exist (ha).
So for exemple, let's take chickenpersons; their own society is based around how chicks really behave in groups. Most of their civilization is composed of hen managing ressource gathering and craft-making, whereas roosters battle to have the dominant role and are more likely to be soldiers or nobles. Their clothes and attire could look very sophisticated and clean, and have high regardS of great craftmanship/craftdwarfship. So if you were to trade with them, they would expect quality work coming from you. They would also have one of the fastest growing communities as they usually have many children.
They could be allied with other bird-people, such as duckpersons, who could be less social and prefer to have a quieter existence, if not just travel at all times, and maybe some duckmen would be solo adventurers who look for danger.
Most other bird-people would be very migrating races and fly around, but also have a strong sense of family-bonding.
Let's take reptile-men. I wouldn't go for the same as Skyrim's honestly. I think Reptile men would be more secretive and be able to form bonds with one another, hiding their bodies behind cloaks and a whole lot of rich ornamental clothing. They would be very talented regarding certain things, such as crafts, martial arts or politics/trading. They would make good fortress neighbors. However, they would rarely reproduce and give birth to a single lizard they would treat with much care, like personaly educating him or her (or it, since some lizards don't have any gender). Turtle-men, Tortoise men, Gila Monster men and Gecko men would also be included in their communities. They could also have distinctive traits, like weird ears, eyes, different types of claws or more arms and legs, maybe even a beak.
Rats would live in mass underground, or be allied to the goblins. They would also probably live in caverns or lairs like Kobolds. I dunno, I like Skavens.