We present a highly nonlinear system of partial differential equations to investigate the role of quorum sensing (QS) in biofilm resistance against antibiotics. The model is studied in computer simulations to identify key parameters that influence the relationship between QS and biofilm resistance to antimicrobial agents. Our results suggest that an adaptive, quorum sensing controlled mechanism to switch from fast growth with reduced antibiotic resistance to an antibiotic resistant slow growth regime may confer benefits to biofilm populations.It enhances the formation of micro-niches in the inner regions of the biofilm in which bacteria are not easily reached by antibiotics. Whereas quorum sensing inhibitors can delay the onset of increased resistance, their advantage is lost after induction occurs. This emphasizes the importance of timing for treatment of biofilms with antibiotics.