Describe the pearl as being a colonial animal?

A town is described as a "colonial animal". It is separate, individual, linked within itself. The group exists as a whole..... the news or gossip spreads quickly.

A town is a thing like a colonial animal. A town has a nervous system
and a head and shoulders and feet. A town is a thing separate from all
other towns, so that there are no two towns alike. And a town has a
whole emotion. How news travels through a town is a mystery not easily
to be solved. News seems to move faster than small boys can scramble
and dart to tell it, faster than women can call it over the fences.