Invention of fire - In the entire stone age, fire was produced by rubbing stones. This period is believed to be from 2.5 million years before the modern period to 12000 years ago.
It is believed that the primitive man would be carrying stones somewhere, then suddenly he would have seen the spark generated by the collision of two stones and from here fire was invented.
At first they were afraid of it but later they started using it very well.
They started using it for lighting, scaring animals, and cooking meat etc.