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.
The conversion of one differentiated cell type into another does not occur as it does in control animals. In C. elegans, the Y cell undergoes a dramatic redifferentiation from being a cell in of the rectum to a PDA neuron. This transdifferentiation requires the cell to withdraw from its established position, migrate, and then become a motor neuron.