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Let's see,
You might know that if the cat crosses the road then it will be bad luck for you. But that's not the case.
In the olden days the people used to travel by the bullock cart or by walking for travelling in forest. So, if the black cat crosses their path then the bullocks or horses get scared of them. In the night, the eyes of the cat shines and in the dark they cannot see properly. So, they could be predators like lions and tigers which can easily confuse them.
The another reason is that, the cat that comes in the front of the carts can be chased by any animal which can also cause harm to them. So this could be the reason behind this superstition.
The people of olden times used to believe this superstitions blindly and this is followed by their next generations also.
But the reason behind believing this superstitions is that fear. Means, if you knew the scientific reason behind the superstitions then also you believe them because of your thinking, you think that if we did not follow it and something happened to us then what will happen.
The superstitions are believed only because of fear of it. So, the superstitions have scientific reasons behind but all of them are not useful, some of them have no reason behind and thoughtlessly followed by the people.
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