Different animal communities have evolved sharing between different age groups of responses to external threats. Elderly individuals commonly oppose attacks with their deaths.
Termites live in mounds and can be invaded by other termites or encounter infections. There are castes that perform different tasks for the community: queens and drones for reproduction; soldiers for defence; water carriers; workers. Generally, younger individuals do lower risk tasks, protected in underground chambers, feeding larvae and tending fungi gardens, where wood is digested in some species.
Older individuals are not as effective at nurturing larvae or nest maintenance and work outside defending against foreign species in high risk situations. Their mandibles have worn with age and cannot be sharpened by moulting. They carry toxic swollen pouches in their abdomens, like backpacks, holding copper-containing blue crystals. When attacked they explode and the enemy is showered with toxic chemical excrement. After grooming to remove harmful organisms, they cannibalise cadavers, unless they are infectious and buried.
https://www.nature.com/news/termites-explode-to-defend-their-colonies-1.11074
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