>Holldobler and Wilson – The Ants – 1990 – Describe a triangular relationship between ants, caterpillars and flies.  The caterpillar exudes a kind of nectar on its skin.  The fly lays its eggs on the caterpillar, thereby becoming a predator through its larva.  The ant is a predator on the fly, and is also attracted to, and consumes the caterpillar’s nectar.  When the caterpillar is surrounded by ants, it suffers much less predation from the fly.  In effect, the caterpillar trades some of its resources for protection.
>If the top predator, the ant, dies out, it leaves an oscillatory predator – prey relationship between the caterpillar and the fly, as described by the Lotka-Voltera equations.