Animal Swarms?
Last summer there were a number of unusual swarms of animals that made the news. These included huge schools of sharks loitering around beaches, and clouds of trillions of tiny aphids falling on the city where I live.
Greg Bear in his book "The Forge of God" and "Anvil of Stars" depicted the potential sentience of collectives where a single member of the species is not. For example catarpillars are dumb, but if they had the tendancy to congregate and communicate effectively, they could become intelligent.
Just having a thought here. Comments?