Not many animals live in houses, and even fewer know how to build a nest or a den. The majority simply make use of natural holes or the homes of others, those extraordinary animals able to weave plant fibres, shape clay, or design labyrinths against predators and floods. Making traps is even more complex and unusual.

Taking care of one’s children is one of the hardest jobs in the world. There are times when you can almost understand that some animals don’t take care of their offspring at all. Vultures oblige their young to leave the nest, spiders do their best not to eat them, while snakes do not care at all for their offspring.

During their lives, animals spend tonnes of time taking care of their personal appearance. They scratch, lick, powder themselves, or comb their feathers and take baths for hours, every day. This personal hygiene can establish incredible frameworks for relationships, sometimes creating lifelong friends.

Animal’s diets have evolved in such amazing ways. Snakes don’t eat much, some can go without food for a whole year, but when they get to it, they can swallow preys many times bigger than their heads. Some species have the opposite strategy: ruminants never stop eating, but they have to secrete more than 100 litres of saliva a day!

Living means struggling and fighting. It means winning and losing many battles, both big and small. This struggle affects everyone and everything: fights over food, over territory, or for love. Nevertheless, violence in nature is often just a ritual that follows a protocol, a set of rules and formalities that almost always prevents serious injuries. But not always…

The most common relationship among living beings is that predator and prey. But it’s not the only one. There are non-violent relationships, and many more that we could consider to be cooperative and beneficial for both sides. Nonetheless, friendship is always beneficial: food, free transportation, or protection are the tradable; the things that make them friends for life.

The strategies that wildlife use to reproduce are hugely varied. Sometimes starfish are simply broken into pieces, while aphids can be born from an unfertilized egg. There are animals that spend their whole lives with one mate, others that are only faithful to their partner some of the time, and still others that are already breaking up when they’ve just met.

Animals employ techniques of deceit to hunt or to escape from those who hunt them, some so sophisticated they can be considered lies. Animals’ shapes and behaviour have evolved in surprising ways, turning them into living traps. The ant lion, alligator turtle, bombardier beetle and the anglerfish, use lures, disguises or even hi-tech constructions to survive.

Sleep is as crucial as it is unexplored and unexplained. The range is vast: all living things sleep, but some for just a few seconds at a time, others for more than 90% of their lives. A six-eyed spider can stay still for months; snakes never close their eyes; dolphins even speak while sleeping. This is a truly eye-opening documentary.

Human language and the forms of communication of animals are separated by such an enormous abyss that probably no other species will ever cross that gap. Nonetheless, the beautiful, complex, and diverse mechanisms that evolution has designed to allow species to transmit and receive messages are fascinating. Using almost all the senses – hearing, touch, smell, and sight – living beings convey information.

The biggest show on Earth is wildlife in action. Fight, communicate, build, love, breed, and eat: these are the basic animal behaviours. This series treat them all, one by one. We explore some unknown species, and others that are common enough to live among us, but whose behaviours can still surprise us!