DICE — MAMMALS OF SOUTHEASTERN WASHINGTON 
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to wander far from water. Bailey (l900, p. 3l) reports one specimen from Fort 
Walla Walla. At Pullman their runways are common in the grassland of the 
tops and slopes of the hills. April 1, 1913, a female with eight very small 
-embryos was taken in brush beside the Touchet River near Prescott. April 6 
another female caught in an alfalfa meadow contained six well-developed embryos 
each about 22 mm. in length. Half-grown young were common as early as 
April 1 in that year. 
April 6, 1913, a set of workings of this species in an alfalfa meadow near Pres- 
cott was dug out. Fresh surface runways extended in several directions 1 to 3 
meters from a group of three holes which were not over 50 cm. from each other. 
The three holes were the openings to three tunnels which connected together 
near the underground opening to a fresh nest. The nest was composed of dried 
grasses and its top was several centimeters below the surface of the ground. The 
passages were fairly intricate, but not long, and in a blind alley a female heavy 
with young was found. The previous day a large male had been trapped near 
the entrance to one of the tunnels. As this system of workings was at least 50 
meters from any other group of workings the evidence is strong that it was con- 
structed and occupied by a single pair of mice. In a set of tunnels beside an old 
fence, partly dug out on April 13, one tunnel ran underground for more than four 
meters and had several branches. A fresh underground nest filthy with excreta 
connected with the tunnel. A young individual was captured in the tunnel. 
Captives are very fond of raw potatoes and also eat oatmeal and to a slight 
extent grains of wheat. 
Microtus mordax mordax. Biting Meadow Mouse. — Very abundant in the 
first week of August, 1914, in brush and timber and especially in swampy places 
along Butte Creek. On July 28 one was trapped in alpine fir forest on the top of 
a ridge at the head of the North Fork of the Touchet River. On August 9 two 
half-grown young were trapped in brush beside a spring on the ridge at Twin 
Buttes Ranger Station. A female taken on Butte Creek August 5 contained 
two large embryos nearly ready for birth. Half-grown young were numerous 
at the same place on that date. Three were trapped in late May, 1909, in brush 
along the South Palouse River at Pullman. 
Ondatra zibethica osoyoosensis. Rocky Mountain Muskrat. — Hollister (1911, 
p. 36) records specimens from Touchet and from Walla Walla. On June 15, 
1914, one was seen swimming in the Walla Walla River three miles east of Wal- 
lula. A considerable number occur along the Touchet River near Prescott. At 
Pullman a few occur along the South Palouse River and in Silver Lake. 
Rattus norvegicus. Norway Rat. — House rats have entered southeastern 
Washington and are rapidly increasing in numbers. They are common in Walla 
Walla and a few occur in Prescott, and they are spreading along the valleys. 
Mus musculus musculus. House Mouse. — On June 13 and 14, 1914, ten were 
trapped in the willows along the Walla Walla River three miles east of Wallula. 
In the neighborhood of Prescott they are abundant about the houses in town and 
in the valley, and even about farm buildings far out in the bunchgrass hills. In 
the Touchet Valley they are often found about grain stacks and in the timber and 
brush along the river. One was taken May 29, 1909, in brush by the South 
Palouse River at Pullman. 
