Gilpin observer., 1908-10-15

HLIVEJC C/ZSEO N/I5 (TII2/zSEHS
H/D G4LZ E.RIES.
In crossing the prairies of central
and western Kansas the travellers
attention is frequently drawn to the
gravel-covered mounds that skirt the
railways and wagon roads. Located
in the center of cleared circular areas,
they stand out prominently breaking
the grassy surface. These mounds
dot the slopes of ravines, the banks
of streams, and hooks and flats be-
tween cliffs and ridges. They occur
along travelled streets and sidewalks,
in corrals, and in dooryards. They are
present in fields of wheat and alfalfa,
in spite of the plowing and disking.
They possessed the prairie before the
farmer came, and they remain in spite
of his operations. The ant whose in
dustry has made these mounds. with
their clean-swept dooryards, clings
tenaciously to the house which it has
built and, so often as the roof is
destroyed, laboriously rebuilds It.
These ants include a considerable
portion of the western plains in their
range. They occur throughout the
northwestern part of Texas. a con-
siderable part of New Mexico, Arizo-
ma, Utah and Wyoming, the western
part of Oklahoma, Kansas and Ne
braska, and the whole of Colorado.
Although some are perfect cones,
the mounds usually have an ellipiti-
cal base. They are of various sizes
and heights. depending on the age,
size and location of the colony.
The clearing surrounding the mound
is usually circular and regular in form,
ellipitical. 1t is level. absolutely de-
void of vegetation, and usually has the
mound as its exact center. The size
of the clearing depends upon the age
and size of the colony and the nature
of the surroundings. Those in buffa-
10 grass average nine feet in diameter
and those in Russian thistles IL feet.
In alfalfa fields they may measure as
much as 30 feet. and the extreme linn
it of As feet was found in a corral.
The ants cannot tolerate the pres
ence of vegetation near their mounds
and the workers clear it away by use
VI lHtll lilahuipito. my
doubtless find that vegetation is an
obstacle to their going and coming;
that it affords concealment to their
enemies: retains moisture after a
rain, thus favorng the growth of
injurious fungi; that its roots pene-
trate the chambers of their nests and,
decaying, form passageways for the
entrance of water.
They cover the mound 10 a depth
of from one-half to one inch with a
layer of coarse particles selected from
the surrounding material. making the
slope nearly as steep as the nature
of the substances will permit.
The dexterity and ease with which
the workers handle the pebbles where
with they cover their homes is n
source of constant interest and sur
prise. A worker will seize a pebble
with outstretched mandibles and. with
head elevated. holding it well to the
front, carry it over the rough surface
to the very top of the mound without
once stopping to rest In no case
does one worker help another that
happens to have undertaken too heavy
lOuu. we nave oteH suCH
uals struggling vainly at the base
while their comrades pass uncon-
cernedly up and down all about them.
Beneath the gravelly coating the
mound is composed of the local soil
mainly brought up from below, and so
firmly cemented together that 1t forms
rain.proof roof. Except for an un
broken layer just beneath the gravel
ly surface, the whole mound is honey
combed with chambers and galleries
The ants by no means restrict them
selves to their mound. but penetrate
the soil directly beneath 1t to a great
depth. sometimes as far as ten or
more feet. The circular chambers,
with their low arched ceilings and
level floors, vary from one to three
inches in diameter and from one-half
| to one inch in height. The connect
| ing galleries have n uniform diameter
of about three-eighths of an inch and
vary in length with the distance be-
tween chambers. Beyond the first
three or four inches below the base of
the mound the chambers decrease
markedly in number and In proximity