KnowHow team explains: Often we find bulls getting agitated if a red cloth is waved before them. But in reality, bulls like many other animals (such as cats and dogs) are colour blind, which means they can not differentiate one colour from another. All colours, be it red, blue or green, seem grey or black to them.

The idea that bulls get agitated on seeing a red cloth being waved at them originates from the popular practice of bullfighting in Spain. In this game, the Matador (the person fighting the bull) uses a red flag or a red cape to provoke the bull. But the bull does not charge because of the colour of the Matador’s cape; it does so because of the movement of the cape.

In this typical Spanish game, a Matador will don his Montera (small black hat), bow to the President’s Box, and then dedicate the bull to a spectator in the stands. He will start the fight with a series of passes, first from side to side to bring the bull close to his body, then high with the cape travelling directly over the bull’s horns.

After the bull is trained to charge the cape and it has reduced its area of protection to just a few feet, the Matador will show the spectators his individual personality by variations on these passes. Some of the better Matadors will fight the bull from knee-level or even kneel with their backs exposed to the bull.

It has been proved experimentally that even if a white piece of cloth is used to provoke the bull, the result would be similar.

In our daily-to-day life, whenever we are dressed in red and see a bull coming towards us, governed by psychological reasons, we tend to blame the colour of our attire. Such is the internalisation that the expression, seeing red, is used to convey anger.

The question was sent by Koel Bandopadhyay via email