Is gaining a 'sixth sense' one of the rewards of appreciating nature? The recent Tsunami in December 2004 that devastated parts of Indonesia, Thailand and Sri Lanka renewed interest in the seeming existence of a sixth sense in animals. One of the devastated areas was an animal reserve at Yala in Sri Lanka with monkeys, leopards, buffalo, elephants and 130 species of birds. But after the Tsunami and the unfortunate death of many tourists, virtually no animal carcasses were found. How did the animals escape the tidal wave? Animals were reported to behave strangely long before the Tsunami struck. Some observations were that elephants screamed and ran to higher ground. A dog refused to go for its beachside walk. Flamingos breeding at Point Calimere wildlife sanctuary in India abandoned their nests for higher ground before the tidal wave struck. And zoo animals remained in their shelters. The problem with some of these observations must be that they are coincidental, but become remembered as evidence of a sixth sense upon association with such a significant event. A bit like people who thought Uri Geller could mend watches by channelling psychic powers through their TV set. A small percentage of 'broken' watches will always work for a while if tested again, and these are the examples that would get reported, rather than the majority of boring failures.

There have been other examples of animal sixth sense. For example, strange behaviour by animals in 1975 in the Chinese city of Haicheng led officials to evacuate the city, which saved thousands of lives when a large earthquake struck a few days later. Similarly, it was recorded that before an earthquake struck Helice in Greece in 373 B.C., animals such as dogs, rats and snakes fled the city. A medical doctor in Japan in September 2003 claimed that he could predict earthquakes when the behaviour of dogs became erratic and anxious.

A number of influences appear to have been lumped into the sixth sense basket.

1. An enhancement of the five senses
Many examples of what people call a sixth sense, are probably just enhanced versions of the stable of five senses, sight, hearing, taste, touch and smell. When dogs react to sounds beyond those heard by humans, they can appear to react with no information, so have forewarning. But this is not really a sixth sense, but higher scaling in their sense of hearing compared to humans. Bats emit ultrasonic waves, beyond human hearing, to echolocate prey (like radar). Similarly, canaries are more sensitive to the smell of methane than humans (I'm not sure if they can actually smell it so would leave if they could, or if it is odourless to them but they are more sensitive), so when they keeled over in coal mines, humans knew it was time to leave. A variation on touch is the ability of many animals to feel seismic waves through the ground by means of corpuscle sensors in the joints. Elephants are particularly sensitive, perhaps as they can locate other elephants based on the seismic shockwaves that their mass produces. They may also communicate by stomping the ground. Therefore, they appear to detect earthquakes long before many other animals, and flee from their direction. The seismic shockwaves from tremors pass through the earth most vigorously as Rayleigh waves, and many animals can detect them. Humans can detect Rayleigh waves (tremors, vibrations) through pacinian corpuscle sensors in the joints, but perhaps people are not attuned to them. Scorpions are also particularly sensitive to vibrations in the ground (from prey), and they locate the seismic waves by numerous tiny slits in their basitarsi (basitarsal compound slit sensilla or BCSS). Many vertebrates including mammals have an extended sense of smell through the Jacobson's organ (=vomeronasal organ) which can detect even more minute quantities of chemicals, such as pheromones. Some call this a sixth sense. Snakes increase sensitivity by inserting a tongue laden with chemicals from the air into the paired pits of the organ (the paired organs required a forked tongue). Humans may also have rudimentary VNOs, which apparently occur as small pits inside the nose. They may now be redundant, or have some sensory function, hence the interest by perfume manufacturers.

2. Additional sense.
Perhaps the 'sixth sense' should be a genuinely new sense that is different to the standard five, so has different kinds of receptors. Some animals have additional senses such as for detecting electric and magnetic fields. Muscle movement and the heartbeat in animals produce small electric fields. Sharks evolved receptors around the head to detect these fields, and home in on their prey. Hammerhead sharks have positioned their detectors on a widened head, for greater triangulation. Other fish have electroreception through their lateral line. Monotremes such as the platypus can detect electric fields from prey, which is useful when they sift about the mud for shrimps and yabbies. Some birds such as pigeons can detect the magnetic poles, which helps in navigation. Their heads contain cells with magnetite (iron oxide) crystals that align with the poles like a compass.

3. Psychic intuition
Another version of the sixth sense is of a psychic sense that allows some to foretell the future and read minds. I'm afraid, I don't believe in such things (nor other things either, more beetle). As with all psychic stories, none have been proven, probably because they don't exist, and are a figment of human imagination. What is more interesting to me is why humans want to believe.

4. Attunement or natural intuition
A source of intuition that may be genuine would arise when creatures attune with their environment or niche, so that they become a part of that nature. The gifts would be especially potent if the animal or human could attune to the point of being 'wild. From such an integrated position within the environment, a person would have more direct linkages with initial and subtle information that an estranged person would fail to notice. The attuned person would have greater perception and wisdom, and apparent intuition, for their surroundings. They might appear to have a sixth sense, and know what was about to happen. Attunement intuition is not actually a new sense, but a way of gaining extra meaning or making better use of the existing senses. Indigenous people know where to find food, and when to seek shelter because of signs in the weather, better than a tourist. They might be able to sense when a dangerous animal was approaching, by recognising the silence of nearby animals. A sailor can sense the wind direction better than a land lubber, and guide a fast yacht surely. A black tracker can read signs and find lost children in the bush better than white settlers.

Some level of 'sixth sense' is a prize available to humans if they seek to understand and bond with nature, and realise that nature has more to teach. Of course, it might seem that this sixth sense is only needed in nature, or to avoid the rare tsunami, so most humans should be able to live without it in their artificial and padded world, where even second rate and clumsy minds will survive. But an attuned mind is a more enjoyable mind. It will be more astute and sharp, and will be able to take pleasure from a greater range of environmental stimulations.  (posted May 2005)

HomeIndexBiology Lesson
Do Animals have a Sixth Sense?
By Dr Beetle