Animals and Magnetism
One of the things people may have noticed about insects is that it is very hard to get the, to change their general direction. Even if you frighten them away with your hands, they have a tendency to come back. You might think that they are seeking food and following their natural instinct to fly towards it. Very often that is the case, but not always.
This sense of direction is especially prevalent in bees but it is found in other insects too. This same directional instinct is found in birds. Again, you might think that this is because of their ability to see things from above and use landmarks. No doubt this bird’s eye view is very useful to them. But even if they can see further, the earth’s curvature creates a horizon beyond which even they can’t see. Yet this does not prevent homing pigeons from flying back to their home.
Furthermore, fish and other sea creatures also exhibit directional sense. Sharks have a very strong sense of direction, quite independent of their food hunting instinct. The same applies to ray fish. And of course Salmon are able to return to their birthplace to breed, even swimming upstream in order to do so. And whales are known to have a very powerful sense of direction.
A lot of research has linked these directional senses to earth’s magnetism. Magnetic particles have been found in the brains of many of these creatures and we know that in the case of bees and homing pigeons, magnetism is the key mechanism that guides them.
Two research scientists, Albert R Davis and Walter C Rawls wrote a book called Magnetism and Its Effects on the Living System in which they detailed some of the research they had conducted on the subject. In one of their experiments, they exposed fertilized chicken’s eggs to the north or south poles of magnets, using a third group for control. They found that group exposed to the south pole, hatched 2-3 days before the control group, whilst those exposed to the north pole hatched 1-2 days after the control group.
After the chicks were hatched, they were put into separate cages for each group. Inside the cage, the researchers placed a real and a fake horseshoe magnet in each of the three cages. The size of the magnet was 15 x 13 cm and the poles were 6.5 cm apart.
The chicks that had been exposed to the south pole placed themselves between the poles of the real magnet while still wet and waited for two minutes before moving away from the magnet and staying as far as possible thereafter. Those exposed to the north pole did likewise, but stayed between the poles for about five minutes. Finally those that had not been exposed to magnets in the egg stage waited until they were dry and then placed themselves between the poles of the magnet for two and a half to three and a half minutes. None of the chicks went for the fake magnet, though it was made to look identical.