I’ll Scratch Your Back, If You Scratch Mine

Ants provide interesting examples of insect co-dependence.  Some species keep aphids in a special section of the nest, building little enclosures to hold them like dairy farmers keep cows in a barn.  If danger threatens, the ants carry the aphids to safety.

One species actually brings aphid eggs into the nest, tending them with as much care as their own eggs.  When the eggs hatch, they put the aphids out to pasture, moving them from one plant to another until they are ready for milking.  When ants milk aphids, they stroke their bodies with their antennae until the aphids release droplets called honey dew. The worker ants collect this fluid to feed to their queen.

The blue butterfly provides another example of co-dependence.  This insect is now extinct in Britain but is still seen in some parts of Europe.  After hatching, the newborn caterpillar feeds on leaves for about three weeks.  Then it falls to the ground to await discovery by passing ants.  When the ants find it, they carry it back to their nest.

As the ants stroke it with their antennae, the caterpillar releases chemical scents which convince them that it’s one of their own.  The caterpillar also secretes a sweet syrup that the ants like to eat.  It stays in the ant’s nest for ten months, gorging itself on ant eggs, and providing food for the ants, until it emerges as a butterfly.

So next time you need to cooperate, think ants and respond!