THE POCKET RATS. 



Rats and mice seem to enjoy living in 

 localities that are frequented by but few 

 other animals. They are also adepts at 

 seeking- food supplies and travel long dis- 

 tances when hunger demands and a sup- 

 ply of food is not at hand. The Pocket 

 Rats are nO' exception to this rule and 

 some of the species live in dry, arid re- 

 gions where but little vegetation grows, 

 aside from a few species of cactus. The 

 rat of our illustration was found by Mr. 

 Frank M. Woodruff in such a locality, 

 where it had hidden under the sheltering 

 branches of a cactus. 



The marked characteristic that gives 

 these little animals their name is the 

 pockets or cheek pouches. These are 

 external openings outside of the mouth 

 and are lined with a furry skin. They 

 are ample in size and the tw^o will hold, 

 in some instances, a heaping tablespoon- 

 ful of grain. "The filling is done so rap- 

 idly that, where a hard grain like wheat 

 is used, a continuous rattling sound is 

 made. The ejecting of the grain from 

 the pockets is aided by a forward, squeez- 

 ing motion of the fore feet, each foot 

 making two or three quick forward passes 

 Some of the species seem to thrive in 

 captivity, and after a few days do not 

 fill their pouches, apparently having 

 learned that it is a useless labor. When 

 obtainable, their natural food consists 

 of various plant seeds, but when in the 

 neighborhood of cultivated fields and the 

 vicinity of houses, they feed also upon 

 grain and the vegetable waste from 

 camps and houses. Mr. F. Stephens says 

 that some of the species, whose habits he 

 has studied, will eat about a heaping 

 tablespoonful each of wheat or barley 

 in twenty-four hours and one or two 

 square inches of beet or cabbage leaves." 

 As they are often found in regions prac- 

 tically devoid of water, a large part of 

 the year, it is highly probable that they 

 obtain the necessary moisture from suc- 

 culent leaves. In captivity they drink but 

 little water. Mr. Stephens writes of one 

 that he trapped that was evidently very 

 hungry. Placing it in a cage he gave it 

 grain. He says : ''It was amusing to see 



the eagerness with which it immediately 

 went to filling its pockets. It stuffed 

 them so full that it must have been posi- 

 tively painful, and then it. would not stop 

 to eat, but hunted about for some exit; 

 not finding one, it ejected the contents of 

 its pockets in a corner out of the fire- 

 light and went back for more. This time 

 it ate a little, but soon gathered the re- 

 mainder and deposited it with the first. 

 After eating a little more, it refilled its 

 pockets and hunted about for a better 

 place to make a cache, seeming to think 

 its first choice insecure. These actions 

 plainly show that they are in the habit 

 of storing away their supplies." In some 

 fields where they are common it is said 

 that more than a pint of grain is 

 ploughed up in a single cache. 



The elongated hind legs, well pictured 

 in our illustration, give these rats a won- 

 derful power of locomotion. x\s they 

 leap rather than run, they are often called 

 Kangaroo Rats. Mr. Woodruff states 

 that the specimen, which we have used, 

 when trying to escape started with short 

 leaps, but as it gained headway the spans 

 were about four feet in length and at 

 the highest point about eighteen inches 

 from the ground. He found them quite 

 common in the vicinity of San Diego, 

 California. They are nocturnal in their 

 habits, seeking their food through the 

 twilight and night hours, and resting 

 during the day in their burrows or in 

 shaded places near tlie openings to them. 



When resting the position of the feet 

 and the arched back give them the ap- 

 pearance of a hairy ball. The tail is laid 

 straight out from the body, if space will 

 permit, or when the quarters are 

 cramped it may be curled alongside the 

 body. The tail is quite useful, as it is 

 used as a sort of brace when the animal 

 raises on its hind feet to view its sur- 

 roundings. 



There are a number of species of these 

 interesting rats. The first one was dis- 

 covered and named in 1839. The species 

 we illustrate was first found near San 

 Diego and named Dipodomvs similis in 

 1893. 



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