Some termites grow up to be suicide bombers. Researchers observing the termite species Neocapritermes taracua found that certain workers, when they became elderly, grew a pair of dark blue spots between their abdomen and torso. When invaders raided their colony, these aging workers bit the intruders and then exploded the blue sacks, releasing a sticky and lethal gel, reports Discover.
The blue color comes from copper atoms inside proteins that are secreted by the termite's glands, explains Discover's Not Exactly Rocket Science blog. Researchers believe that the copper-filled proteins mix with other compounds from the termite's salivary glands to form the deadly chemical weapon. The suicidal warfare is engaged in by old workers who can no longer do regular work.