@ Mrudul ji and Sabyasachi da, Those snakes were showing that behaviour in a swamp adjacent to village road. Villagers were busy for cultivation of paddy in that swamp. So the place was crowded and noisy. So they got disturbed and disappeared into the nearby vegetation. So I was able to click just a few shots. I couldn't get the opportunity to bring the full body of the snakes in one frame. Soon I'll be posting a collage of behaviour of Rat snake taken at different places and in different situations, in Natural history section.
Samrat