[music playing]
NARRATOR: A Nephila spider joining the monsoon banquet.
For her prey, there is no chance of escape.
Her web is strong enough to hold small birds.
But she recognizes this catch.
She snips at her web.
She's caught a Tiger butterfly.
And he is utterly toxic.
Butterfly predators need to learn this.
But his poison protection is ultimately due to the way
that the monsoon has starved these forests,
forcing the trees to battle to protect their nutrients.
A minuscule caterpillar emerged from a butterfly's
egg laid just after the rains.
Food surrounds him, but he faces a formidable problem.
The tree guards its nutrients with fatal poisons.
He begins to chew, but he's not eating.
He is excavating a trench.
The plant fights back, oozing a noxious sap.
But the caterpillar has created a barrier.
The sap pumped from the stem can't reach him.
Finally, he finishes his circle.
The heist is complete.
The portion inside is now isolated and safe to eat.
As he grows, he raids the tree's reserves time and again.
Each time, he ingests tiny traces of poison,
and with each dose, his resistance
builds until eventually he achieves complete immunity.
Now the caterpillar can gorge himself.
He has harnessed the tree's defenses for himself.
Protected by the poisons in his body,
no predator could safely eat him.
And his ostentatious warning colors ensure
that they won't even try.
Safe in his cocoon with poisons coursing through his veins,
the insect is completely protected
through his development and into his second life
as a Tiger butterfly.
[music playing]