62 THE MAMMALS, REPTILES, AND FISHES OF ESSEX.
Mus decumanus, Pall. Hanoverian, Brown, or Norway
Rat.
This pest, although placed amongst our native animals,
did not make its appearance in England until the earlier part
of the eighteenth century, when it was doubtless brought
hither by merchant vessels from some southern country.
Pennant says it came from the East Indies, and he remarks
with prophetic intuition: "It has quite extirpated the common
kind {Mus rattus) wherever it has taken up its residence, and
it is to be feared that we shall scarcely find any benefit from
the change, the Norway Rat having the same disposition as,
but greater abilities for doing mischief than, the common
kind." At the time when the name " Norway Rat " was first
applied to it, this rat was not known at all in that country.
It was called the Hanoverian Rat from its having arrived in
this country about the same time as the first Hanoverian
sovereign. This, no doubt was a witticism of our Jacobite
predecessors.
Its fecundity, cunning, and omnivorous habits enable it
to defy all efforts for its extirpation, and the destruction
wrought by game-preservers on so-called " vermin," by exter-
minating its natural enemies, facilitates its continuous
abundance in many districts. In the light soils of the neigh-
bourhood of Colchester, every hedge has its colony, especially
where the game is strictly preserved.
In many places around the Essex coast, there exist con-
siderable portions of land, sufficiently raised to be above
ordinary high tides, but covered periodically with the sea.
These spots, called "saltings," are frequently occupied by
colonies of the Hanoverian Rat, as are also those detached
pieces which form islands, and which are often named " rat
islands" from this circumstance. How the occupants of
these islands subsist is almost a mystery, for the only vegeta-