Many social insects, like ants and termites, do most of their work with their mouths. After enough time spent cutting through foliage and shoring it around, the mouth parts on older animals tend to wear down and lose their sharpness, making them less able to contribute to their nest. Now, researchers have found the way that some older termites can remain useful to their peers: they become suicidal chemical weapons specialists.
The authors were working with a species that was already known to have a penchant for a suicidal form of defense. When confronted by a competing species of termites, the animals tend to burst, releasing a sticky substance from their backs. However, the authors noticed that a subset of animals had blue stripes across their backs, and were far more prone to bursting with just a bit of minor prodding from an enemy termite.