Bacteria choose to swarm based on what happened to their great-grandparents

Even organisms without brains can remember their past: Scientists found that Escherichia coli bacteria form their own kind of memories of exposure to nutrients. They pass these memories down to future generations, which can help them evade antibiotics, the research team reported in the Proceedings of the National Academy of Sciences USA.

“We typically think of microbes as single-celled organisms [that each] do their own thing,” says Dartmouth College microbiologist George O’Toole, who studies bacterial structures called biofilms. In reality, bacteria frequently survive by working together. Much like honeybees relocating their hive, colonies of bacteria in search of permanent homes will often travel as collective units called swarms.