Case enlargement in Neochlamisus is an elaborate process that larvae perform regularly until the case is sealed to the substrate prior to pupation. During this stage of the life cycle, beetles are immobile and are particularly vulnerable to predation.
The development of a protective shell for Neochlamisus larvae involves an elaborate process where they repeatedly enlarge the case until it's securely attached to the substrate before entering the pupae stage.  During this time, the beetle is immobile and vulnerable to predators.