A mob of bacteriophage attacking E. coli The oval object that stretches diagonally across the micrograph top-to-bottom is a single bacterium. The much smaller and far more numerous round guys, practically paving the surface of the bacterium, are the bacteriophage heads.A mob of bacteriophage attacking E. coli The oval object that stretches diagonally across the micrograph top-to-bottom is a single bacterium. The much smaller and far more numerous round guys, practically paving the surface of the bacterium, are the bacteriophage heads