The tuber begins its growth with the swelling of the seedling hypocotyl. Later, the cavities are formed when cork-generating meristems arise in the inner parenchymatous tissue forming a cork-like wall, cutting off carious shaped and sized enclosures.
Future ant inhabitants may clean out remnants of dead tissue but do not primarily excavate—this has been shown by the existence of chambers in plants to which ants never had access. It has been found that ants are not required for Myrmecodia to form the caudex, or tuberous inner chambers—they exist naturally in Myrmecodia with or without a population of ants.