There are three main phases of biofilm development and rhamnolipids are implicated in each phase. Rhamnolipids are reported to promote motility, thereby inhibiting attachment by preventing cells from adhering tightly to the substratum. During biofilm development, rhamnolipids are reported to create and maintain fluid channels for water and oxygen flow around the base of the biofilm. Furthermore, they are important for forming structure in biofilms; a rhlA mutant forms a flat biofilm. Biofilm dispersal is dependent on Rhammnolipids, however other factors such as degradation of the matrix and activation of motility are also likely to be necessary. It has been shown using fluorescence microscopy that the rhlAB operon is induced in the centre of the mushroom cap, followed by dispersal of cells from the polysaccharide matrix from the centre of these caps causing a cavity to form. A mutation in rhlA causes a failure in formation of mushroom caps at all.