The citizen. (Frederick City, Md.) 1895-1923, 1908-07-31
Rats MAY DESTROY
THE HUMAN RACE
SO Says Dr.. a. CaImette, a Frcncr
Scientist Man Must Drive
Out or Be Driven.
S A MIGRATORY RODENT
Assertion Made That a Single Pair
Will Ordinarily Multiply in Two
Years to Fifteen Hundred.

Rats as menace before which hui
nanity may disappear is a theme
developed with disquieting precision
~ DR.. A. Calmette, a French scien-
lst, in La Revue du Mois. of Paris.
)r. Calmettte predicts that mankind
will have to engage in a general war
are on rats before many years elapse
I the world is to continue to be habi-
able. He pointed out that different
countries have different breeds of
ats which are no great menace in
themselves, which, in fact, are often
Useful. The peril comes from the mi
;ratory rat, otherwise known as the
iewer rat, which has been evolved
" civilization, and which follows the
march of man into every cline Rats
If other breeds have been known
.ver since man began to keep re-
;ords of the things around him. The
irst mention of him was made only
1920, when he was a native of
Persia and East India. He did not
invade Europe until the eighteenth
century.
At that time he was driven out of
his old haunts by the widespread
anime in those regions ard of which
ne was largely the cause. Old
chronicles report that millions of the
'ermin crossed the Volga in 1927.
They made their appearance in Prus-
STA in 1850, and first were seen at Paris
.hree years later. The newcomers
we're not welcomed. Within a week
sixteen thousand were slain. This
made no apparent difference in the
'anks of the invaders.
Professor Calmette says that the
sewer rat did not appear in America
Until 1865, when he was first no.
Iced along the coast and in various
;eaports. AS late as 1870 he had
lot yet reached the head waters of
he Missouri. BY 1900 he had gone
up to the permanent ice belt.
At present. the scientist con-
:inues, this migratory rodent is de-
stroying in the West Indies. in the
Azores and in the Cape Verde ISL
ands annually hundreds of thousands
If dollars worth of coffee, banana,
sugar and orange plantations. AS a
sample of what he can do, the case
Of an island in the estuary of the
River Humber is cited This island
was once completely covered with
rich grass. which kept in good condi-
ion all the year round about 5000
head of cattle. The island is sepa-
rated from the shore by half a mile
Of water. One day the place was in
Tested by rats that had reached the
Island by swimming. That was fif-
teen years ago. To-day there is not
enough verdure on the island to
nourish rabbit. The whole island
has been honeycombed by the ro.
dents, so that it cannot even be re.
claimed by cultivation.
In a number of the Channel Isl.
ands. where nothing grows but a few
ferns and moses, there are also
many thousands of rats. How thew
found sufficient food was long mat.
ter of curiosity, but one day a scien.
list, bent on investigating the mat.
ter, dug up one of the numerous rat
holes and discovered, not without
surprise, sixteen large crabs in a
single pocket of the earth. while
there were six in another. The
crabs had not gone there by them.
selves, that was evident, for all of
them had their legs cut off. Investi.
CATION showed that the rats were in
the habit of making their Grabbing
expeditions at low tide. To immobi.
lie their victims and render them
harmless the rats amputated them
as soon as captured. All the crabs
found were still living and in good
condition. Whether the willy no.
dents kept their prisoners fed or not
is unknown.
The sewer rat is perfectly at home
in sea water, and, according to DR..
Calmette, is always ON the outlook
for an attractive ship in which to
take passage for some foreign port.
He will wait patiently until nightfall
and then swim out to some Yacht
which has pleased his fancy and
crawl aboard by way of the anchor
chain. He is extremely prudent and
is not easily caught. The amount
OF damage these rats do annually in
the cargoes of seagoing ships, in
docks and warehouses would count
up easily into the tens of millions.
They are almost omnivorous, eating
everything from meat and poultry to
the bark of young trees. They have
been known to kill ducks and chick
ems that were almost fully grown.
They are also great egg stealers.
They have even been known to at
tack children and old people. 1t is
reported that a few years ago these
hardy quadrupcds organized a regu-
lar expedition against the Pitie Hos
pital. They were only banished
after the nurses and physicians in
charge had used hundreds of pounds
OF sulphur and disinfectant.
Everybody is familiar with the
stories of how rats carry disease
germs from one part of the world to
the other. These stories are per.
iectly true. Extraordinary precau.
tons are taken against rats at Mar.
settles and other Mediterranean
ports, which have learned much b,
tragic experiences in the past.
DR.. Calmette concludes by show.
ing that within two years single
pair Of rats will ordinarily uulfini,