When I was a young person at school they taught us that we had five senses, but I would argue today that they have overlooked a very important sixth sense, which is the sense of balance. The sense of balance is absolutely essential to upright walking animals like human beings, and we achieve balance using some senses that are located in our inner ear, in the vestibular apparatus where we have the equivalent of accelerometers and gyroscopes that provide the information to keep us upright. Balance is absolutely critical and the human being’s sixth sense.
Other animals have evolved different sensing modalities to those the humans have. For instance, small flying animals like bats have the sense of echo location; they send out pulses of acoustic energy and listen for the reflections and they use this when they are flying at quite high speed at night to find obstacles that they would want to avoid and to find insects that they would wish to eat.
Sharks create an electric field around their body and then they can sense disturbances in their electric field, which are caused by fish swimming in close proximity to the shark’s body, and this is really useful for them in order to detect sources of food.
Finally, pigeons have got an innate sense of magnetism. They have magnetic senses in their heads that allow them to tell where north is and this is absolutely essential for them in their flying long distances, an essential navigational aid.
Now for us, it’s almost impossible to imagine what a sense of ‘northness’ feels like, but pigeons have that sense, so there are many, many, different senses that animals have evolved over time to help them perform the essential functions of life.
All animals have a variety of senses that help them in everyday life. We’ll talk about interesting non-human senses that some animals possess and the often overlooked human sense of balance which is based on accelerometers and gyroscopes in our vestibular system.