Invertebrates make up the vast majority of animal species on Earth, yet most are small enough to go unnoticed underfoot. David Attenborough narrates this five-part series built around them, using close-focus and macro camera work to bring insects, spiders, worms, and other small creatures up to a scale where their behavior reads clearly on screen. Episodes track specific lives rather than general facts: a trapdoor spider ambushing prey from a hidden burrow, army ants moving in coordinated columns, glow-worms signaling in the dark, and the courtship and combat rituals that play out in leaf litter and soil most viewers walk past without a glance. The series argues, through accumulated detail rather than narration alone, that these animals colonized nearly every environment on the planet long before larger creatures arrived and that their numbers and adaptations still shape ecosystems from the ground up. The photography itself, capturing behavior invisible to the naked eye, is much of the reason to watch.