pathogen adherence variant biofilm absent head Animals can move thorough a lawn of bacterially produced biofilm without accumulating an enormous amount of biofilm on its nose. When C. elegans is exposed to certain bacteria (e.g., Y. pestis), a biofilm accumulates on a worm's head. The presence of this biofilm inhibits feeding by the worm, and thereby prevents growth. C_elegans_phenotype_ontology Bah WBPhenotype:0001420