Learn how rain transforms the area into a lush grazing pasture, creating an abundance of food. Moderate weather makes it harder for predators, as prey can migrate further. With plenty of food available, mating and birthing seasons have arrived.
The third instalment examines the spiders and others that produce silk. Attenborough visits New Zealand's Waitomo Caves, which are inhabited by fungus gnats whose illuminated larvae sit atop glistening, beaded filaments to lure their prey.
Thanks to new technologies combining genetics, ethology, geology and even particle physics, paleontologists can now recreate the missing branches of the tree of life. Because of this, it has been discovered that prehistoric mammals were more varied and numerous than previously thought.
A close-up view of sex, bug-style, as David Attenborough talks viewers through the different ways in which creepy-crawlies reproduce. Size matters for the minuscule male orb spider, creepily sneaking up on its intended and trying to mate without her noticing, while there's no rest for the lothario-like butterfly, which has plenty of notches on its proverbial bedpost. However, the harvestman spider has no use for sex at all, and reproduces by cloning itself.