The meaning of "hang out"

The paragraph below comes from a book, The Blank Slate. The quoted part of this book is about the non-zero-sum games, the cooperation that benefit both parties involved.

I want to ask two questions.

1. the meanig of 'society'
I checked out it and found out the corresponding meaning below.
Am I right? (I just want to make 100% sure about it, because it is closely related with next question.)

[Biology] A colony or community of organisms, usually of the same species: e.g. an insect society.

http://www.thefreedictionary.com/society

2. the meaning of "hang out"
What I want to ask you about is the meaning of "hang out in" in the last sentence. It's seems to agree with "team up in," and "agglomerate into" in terms of context. However, I cannot find out its exact meaning in a few dictionaries I have. Can you give me a comment, with an example sentence if you can?

Thanks.

Repeatedly in the history of life, replicators have teamed up, specialized to divide the labor, and coordinated their behavior. It happens because replicators often find themselves in non-zero-sum games, in which particular strategies adopted by two players can leave them both better off, as opposed to a zero-sum game, where one player’s profit is another player’s loss. An exact analogy is found in the play by William Butler Yeats in which a blind man carries a lame man on his shoulders, allowing both of them to get around. During the evolution of life this dynamic has led replicating molecules to team up in chromosomes, organelles to team up in cells, cells to agglomerate into complex organisms, and organisms to hang out in societies.