The first ones advanced cautiously, sniffing the wind that rolled over the seedy grasses high above their heads, but they were followed by a confident multitude that advanced like the tide. Across the grassy meadows, over the forested mountains and like a floating furry carpet they swam the streams, lakes and rivers. The wildlife fled or was swarmed and eaten to the bone. Then the bones too were gnawed to emerge later as sparkling white droppings. The rats did stop often to reproduce but as a mass they just kept on rolling along. It was a wide and wild land but it went down before their flood like grass before a scythe. The trees too were consumed: their roots were undermined by the tunnels that riddled the soil or were chewed from the bottom up until they fell. That pace of destruction could not go on for long.
When the only food left was other rat protein, the army fell to warring on itself: starvation, madness and then finally their flea close-companions passed on the plague. The land lay totally stripped of vegetation and covered with a rotting mass of corpses. There were no survivors.
The winds blew a hot fetid breath over the land. Deluges eroded the pocked soil, eroded the unprotected hilltops down to their rocky bones and filled the valleys with sand. A long time passed. Winds, rivers, migrating birds that dared to rest, brought the first seeds. It must have been like this when the glaciers receded at last and a green carpet crept once again northward. The landscape could not be as it had been pre-rat, but once again trees rustled along the river banks, fish filled the waters and waving grasses clothed the naked uplands.
The next ones advanced cautiously across the grasslands on horseback, weapons at the ready for danger in this new world they had discovered. Back behind them, the great wagons rolled confidently forward bringing the rest of the tribe, the herds of cattle, flocks of sheep and goats. This time it was the wain-rider`s turn to be taking this land. The only danger here was themselves.