NOT all creatures huddle together for protection when under stress. Blast
common soil bacteria with sunlight and they move away from each other as fast as
they can.
Arshad Kudrolli, a physicist at Clark University in Worcester, Massachusetts,
and his colleagues were studying how Bacillus subtilis responds to damaging
ultraviolet light. They bathed a Petri dish of the bacteria in UV light, except
for a circle of shade which they moved slowly around the dish.
As expected, bacteria in the shaded patch followed it around. But oddly, all
the other bacteria fled to the edge of the Petri dish, even…
