Someone just PM'd me saying I know more about butterflies than gnats. I assume this was a tactful way of suggesting I change the topic. So I will.

It happens that I do know more about butterflies than I do about gnats ... even tho I am learning to love gnats.

The big mystery about butterflies is how they manage to transmit navigational information to their offspring so they can make that awesome trek from Canada to a small mountainous region in Central Mexico [then back again] every year.

Some time ago, I read that a researcher found something in a butterfly's brain which might pick up the magnetic field of the earth.

This metallic-like substance might allow a butterfly to "read" the terrain it is traversing.

But, even so, how does that "map" get transmitted to the offspring? It takes about 7 generations of Monarch butterflies to complete a single migration.

Somehow, each new generation is born with "the map".

How is that possible, especially when you consider that each new butterfly must have the complete map even tho that butterfly can only make a fraction of the complete journey?

Does anyone know more about this mystery?