You searched for: “phragmosis
phragmosis (s) (noun) (no pl)
The condition in which the head or tip of the abdomen is truncated and is used as a living plug for the nest entrance: Phragmosis occurs in ants and termites, usually in the soldier caste, in order to close the burrow or nest.

This entry is located in the following unit: Ant and Related Entomology Terms (page 16)