The 'Swiss cheese' instability of bacterial biofilms
  We demonstrate a novel pattern that results in bacterial biofilms as a result of the competition between hydrodynamic forces and adhesion forces. After the passage of an air plug, the break up of the residual thin liquid film scrapes and rearranges bacteria on the surface, such that a Swiss cheese pattern of holes is left in the residual biofilm. 
Hongchul Jang, Roberto Rusconi, and Roman Stocker
physics.bio-ph physics.flu-dyn q-bio.CB