8We all know about the five senses: sight, sound, smell and taste. But there are sounds no human ear can hear, scents no-one can smell, colours our eyes cannot detect, waves of radiation that pass right through us without our noticing ... but known and used by many different animal species. They have their dangers as well as their uses, but are vital to all life on Earth. This fascinating unseen and secret world is revealed in Catherine Barr's latest book. Fourteen colourful spreads display the impact on human and animal life of: Microwaves Ultra-violet and infra-red light Electromagnetic waves Ultrasound and infrasound Scents and smells beyond human detection Understanding these hidden forces enables us to use them in many ways, from photographing babies not yet born, to doors that automatically open, or tracking migratory animals. But many animals also use them. They help cats to catch mice, elephants to find mates, vampire bats to find victims. Ants 'talk' by exchanging smells. Indeed, without 'Invisible Nature', life on Earth would not exist at all.