them.

By degrees the trees of the vale seemed as it were to invade and march
up the hills, and, as we see in our time, in many places the downs are
hidden altogether with a stunted kind of forest. But all the above
happened in the time of the first generation. Besides these things a
great physical change took place; but before I speak of that, it will be
best to relate what effects were produced upon animals and men.

In the first years after the fields were left to themselves, the fallen
and over-ripe corn crops became the resort of innumerable mice. They
swarmed to an incredible degree, not only devouring the grain upon the
straw that had never been cut, but clearing out every single ear in the
wheat-ricks that were standing about the country. Nothing remained in
these ricks but straw, pierced with tunnels and runs, the home and
breeding-place of mice, which thence poured forth into the fields. Such
grain as had been left in barns and granaries, in mills, and in
warehouses of the deserted towns, disappeared in the same manner.

When men tried to raise crops in small gardens and enclosures for their
sustenance, these legions of mice rushed in and destroyed the produce of
their labour. Nothing could keep them out, and if a score were killed, a
hundred more supplied their place. These mice were preyed upon by
kestrel hawks, owls, and weasels; but at first they made little or no
appreciable difference. In a few years, however, the weasels, having
such a superabundance of food, trebled in numbers, and in the same way
the hawks, owls, and foxes increased. There was then some relief, but
even now at intervals districts are invaded, and the granaries and the
standing corn suffer from these depredations.