I was travelling west on the A47 new years eve, and had got to the stretch of road (single carrigeway) about 500 odd yards east of the village of Glaston when my headlights illuminated some 40 to 50 rats in the road. They were crossing the road from right to left, some were stopping midway and turning around, but most were moving from right to left. I could not see how many were on the verge or in the hedge each side, but presumeably many more.It was a swarm of rats , and I can see how folklore like the pied piper of Hameln originated. Anyone know why they do this ? I squashed a few of them .