[forest noises] NARRATOR: In rainforests across the equator, most frogs lay their eggs and abandon them. But one determined frog stands by his young, the reticulated glass frog. It's named for its transparent skin. His organs hard at work, he's got nothing to hide. Mom is nowhere to be found. Dad alone guards the clutch 24/7 until the eggs become tadpoles.

Sometimes this means defending his brood from their worst enemy. Squadrons of carnivorous rainforest wasps take to the air, a deadly threat for a frog. They're aggressive, persistent, venomous, and nearly as big as the glass frog himself. They're not interested in him.

They want his eggs. But dad is not willing to give them up without a fight. He was built for this. [music playing]