It is often said that we humans are the only species with emotions, the only ones who think.

The world is teeming with sentient creatures, which often possess senses which seem miraculous to us. We are not the only species which communicates; every form of life shares a universal language. Living organisms are talking, listening, detecting information and passing messages to one another. Plants are on the move, animals are busily solving their individual problems, while microbes can look at each other with tiny eyes.

Our vision of reality derives from the interplay of the human senses. Many other forms of sense in the living world are not possessed by humankind, and other organisms can detect things in ways that we cannot imagine. Some can sense the earth’s magnetism, watch the changes of polarized light, see heat rays in the dark, or create an image out of ultrasound. Sea creatures construct detailed pictures of their surroundings through pressure waves in the oceans, or find hidden prey through electrical currents in the water. Insects do daily problem-solving. Plants turn in the dark, ready to face the morning sun. Tribes of creatures great and small are bonded by their emotions, and use languages of subtle complexity. Some species use star maps to guide their nocturnal activities. We have a good sense of taste, yet an octopus can sense flavours that are a hundred times weaker than we can detect. A dog has an olfactory sense a thousand times finer than ours. A dolphin has seven thousand times as many light-sensitive cells in its eye than we do. A cockroach is a hundred thousand times more sensitive to surface vibrations than we are. The mimosa plant, rock-rose, and garden pea move when touched, and have more sensitivity than our fingertips.

Mammals experience emotion: zoo animals display neuroses like human prisoners in solitary confinement and dairy cattle, when deprived of their newborn calves, moan in misery for days on end. Mammals dream when asleep. They can show sensitivity and care, altruism and self-sacrifice. A depressed dolphin, recovering in a marine tank from having been caught on a hook, improved dramatically when another dolphin attended to her; holding her with its beak so that she could breathe in comfort.

Birds show cognitive ability. Ravens have been observed to solve problems of feeding from a piece of meat hanging below their perch on a string. By trial and error the raven can work out how to pull up the string and hold it with its claw, time after time, until it can reach the suspended morsel. Ravens play, too. A raven has been seen to slide down a slippery slope on an ice-bound hill, repeating the process as though doing it for pure enjoyment. Birds learn, teach, and communicate. The purpose of the body movements of birds is to transmit messages, and each movement is an expression of its own. Like other expressions, they can be subtly modified in meaning, and can be joined together in a syntactical sequence to convey meanings of greater complexity.

Insects have behaviors that adapt to unexpected or novel situations. Many insects form complex and organized social communities. The honey-bee uses language. Attracted to a dish of sugar water, a bee will start to drink it, spend a while grooming itself, then fly away to its hive. She will run across the hive, wagging her tail, then return in a flattened semicircle to the starting point to repeat the performance. Then she returns in a loop in the opposite direction to the first one and repeats the waggling run once more. Other bees gather to study what she is doing. She has explained distance, direction, and how rich the food source is to the other bees, so that hundreds of bees will be at the sugar water within an hour. If the sugar water is moved repeatedly, the bees will still find it; the bees learned about a new food source and quickly acquire a technique to deal with it.

Squid, cuttlefish and octopus feature some of the most remarkable means of communication in the animal world. They send visual messages to one another via the skin. Cuttlefish signal with rippling changes of colour running along and around their body. Some are threats, some are courtship signals, some are mimicking movements to attract prey, while others are a decoy to throw predators off-guard. Within the skin are coloured cells, orange, red, and dark brown which can rapidly expand and contract. Beneath this layer are a number of uncoloured cells which reflect light with differing intensities. These throw back light to the observer in a range of colours from silver and gold to green and blue. The mechanisms by which the skin changes its colour are immensely complex, and the coordination of the many cells that participate is poorly understood by science.

Beautiful, silverside fish in tropical oceans respond like one living organism. The thousands of individuals in a single shoal turn and twist, passing instantaneous messages to each other and responding at almost lightning speed. They have a finely tuned set of sense which allows the entire community to move as a single entity. Sometimes we see flocks of birds doing this but fish are the masters of the art.

Plants are bursting with movement. They are rich in sensation, and respond to the stimulation of the surrounding world every moment of their active lives. They can send messages to one another about overcrowding or a threatened attack by a new pest. Many plants share hormones that are similar to ours. Plants have pores called stomata which can open and close as the plant dictates. Stomata control the passage of air and carbon dioxide through the network of cells within the leaf. Each stomata is controlled by two guard cells which can open and close the aperture between them. The guard cells can react to the intensity and quality of light, and detect the chemical nature of the atmosphere, then respond to gases. Stomata have the ability to respond to physical stimuli that affect the leaf, like vibrations or movement from the wind. They can sense substances produced by organisms on the leaf surface. These all correspond to four of the classic senses: sight, smell, touch, and taste.

Microbes were the first organisms to appear on earth. Most are invisible to the unaided human eye, yet they can sense where they are going and they can recognize friend and foe. Many boast senses that are superior to ours, and some contain sense organelles of breathtaking complexity. One microbe has a complete and fully functioning eye for example, within its single cell. Some microbes construct homes out of stone, or snare their prey with traps. Bacteria are a few thousandths of a millimeter in size. There are many senses in bacteria, including their own version of taste, and some can sense a magnetic field through particles of magnetite in the cell. In this way, they can swim along lines of force in the earth’s magnetic field in temperate latitudes, and so navigate down through layers of mud to safety. Many bacteria exist in cooperation with other organisms, and adapt their behavior by what they sense of their surroundings. Some bacteria form patterns when they grow, which demonstrates that they may have a sense of position or orientation. Others recognize one another and move together to form communities.

Our aim as humans must be to value the global network of all plants and animals, and to react to their presence with respect. Science has to make the shift from its technical obsession with peering into reductionist crevices, into tinier components of a great and glorious reality. Our modern age is drowning in data. We have more than enough information. The task ahead is to fit our disparate scraps of knowledge into greater syntheses, and learn how living organisms interact. For the twenty-first century we need a new holistic view that unites discrete findings into new patterns of understanding. All life has its language. Our challenge in this new century will be to understand it.