The steamy jungles of the Amazon region reverberate with the sound of screeches, growls and grunts. These are the noises of creatures hidden in the trees vying with one another for survival in the forest. 1.Eyelash viper - So called because of the enlarged scales above its eyes, the eyelash viper hangs in the trees.

From the parched deserts of Southwestern USA to lush forests of the Costa Rican mountains, this episode covers some of the most diverse ecosystems on the planet. The creatures here have adapted to survive in an extraordinary variety of habitats, and that means a diverse array of weapons.

Asia is the largest and most populated continent on the planet. Here people compete for space with some of the most impressive animals in the world. Creatures that have ingenious adaptations to hunt and defend.

Stretching from the North Pole to the tropics, Asia is the largest continent on earth. It is the highest and most populated, and life here is harsh. To survive, the animals that inhabit this continent have evolved into the toughest of the tough.