WILD MICE AND RATS 



83 



the spur roots, standing on their hind legs while 

 they work. Then, with their huge, chisel-like 

 incisors they cut out chips, circling round the 

 trunk all the while, until only the heart of the 

 trunk remains, and the tree falls. 



THE FAMILY OF MICE AND RATS. 



Muridae. 



When their groups and relationships are fairly 

 understood, the wild mice and rats will be found 

 quite interesting. They are so widely distrib- 

 uted it is very desirable that country-dwellers 

 should know something about them, and ap- 

 preciate their good points as well as their bad 

 ones. A moderate effort, properly aided and 

 encouraged, will give anyone a fair conception 

 of the grand divisions of this great group ; and 

 there the general student can stop, if he so elects. 



In approaching this assemblage of North 

 American mammals, the first thought is that its 

 members are difficult to deal with. In some 

 respects they are, but they are by no means as 

 difficult as might be supposed. Like many other 

 new subjects, they yield to a little old-fashioned 

 study. It is not necessary for the general student 

 to enter into the study of a large number of spe- 

 cies. Lay the foundation first by becoming ac- 

 quainted with each genus, and one typical species. 

 Observe the following injunctions: 



1. Treat this bit of study with serious atten- 

 tion. 



2. Learn first the names of the Families, and 

 the approximate size of each Family. 



3. Next learn by rote, in regular order, the 

 common names of the typical examples given. 



4. Learn some of the distinguishing characters 

 of each example. 



5. Study the comparative sizes of the various 

 types. 



6. Finally, in determining the name of a 

 strange species, do not feel that you must name it 

 instantly, or be disgraced! Take time to think 

 over it, and to "look it up." Snap judgments 

 on small creatures have a most annoying habit 

 of proving to be wrong. It is a wise judge who 

 knows when to hand clown a decision. 



In order to make the genera of North American 

 rats and mice clear to the student, I have pro- 

 cured from Dr. C. Hart Merriam, the highest 



living authority on these creatures, a fine, per- 

 fect, adult specimen of the best known (or most 

 typical) species of each genus. Figures of these 

 skins are here reproduced to show their relative 

 sizes, and a life-like illustration of each of these 

 types is also given. In the text, the most strik- 

 ing distinguishing characters are printed in italics. 



With these aids to the text, it should be possi- 

 ble for a clear-headed, keen-eyed student to refer 

 any adult North American rat or mouse to its 

 proper genus. But beware of young specimens! 

 Often they are so puzzling that Solomon himself 

 ould not place them with any degree of certainty. 

 In determining the species of mice and rats, 

 mammalogists depend largely upon the charac- 

 ters of the teeth; but that is a subject too intri- 

 cate for the general student. 



The table on page 84 shows the various Fam- 

 ilies of rats and mice, the North American gen- 

 era, and the typical species of each. It is not 

 necessary for young students to memorize the 

 Latin names of the genera and species; but those 

 who become specially interested in natural his- 

 tory will very soon desire to know them. 



The Muskrat, 1 which received its name from 

 its very pronounced musky odor, is the largest 

 native representative of the Mouse and Rat 

 Family. It is readily recognized by its flat, 

 hairless tail, carried on its edge. It is of large 

 size, measuring about 21 inches in length. It is 

 of aggressive habit, an admirable diver and 

 swimmer, an industrious and intelligent house- 

 builder, and the only native rat whose fur is val- 

 uable. It is found from Labrador and New- 

 foundland to Alaska, and southward to Arizona 

 and Louisiana. 



It is very shrewd in preserving its own life, 

 and even in the large forest parks of New York 

 City, it refuses to be exterminated. When three 

 bogs in the New York Zoological Park were dug 

 out and converted into ponds, the wild Muskrats 

 in the Bronx River found them as soon as they 

 were completed, immediately took possession 

 of them, and there they still remain. Being very 

 destructive to lily bulbs, and most other aquatic 

 plants, their presence in ornamental ponds is 

 very objectionable. 



Muskrats are rarely, if ever, found away from 

 ponds or good-sized streams. They are quite as 

 much at home in the water as beavers, and their 

 1 Fiber zibethicus. 



