Order INSECTIVORA 49 



ber of opossums if it were not for their enemies. Foxes, dogs, 

 coyotes, possibly minks, and large owls pick them off one by 

 one. Although opossums are rather easily caught, they have a 

 unique method of defense. If surprised away from the com- 

 parative safety of trees, they may feign death so that a not-too- 

 hungry enemy may leave them for dead without trying to eat 

 them. Sometimes, however, they are badly mauled before being 

 left alone. Considerable numbers are killed by motor vehicles 

 on highways. Several hundred thousand possums are caught 

 each year by trappers or fur hunters in Illinois, even though 

 possum pelts are worth very little. 



Signs. — Possum tracks, fig. 17, easy to detect in mud or snow, 

 are most apt to be found at the edges of ponds and rivers near 

 woodlands. There is no mistaking them. The print of each 

 front foot shows five fingers spread wide apart, and that of 

 each hind foot shows the large toe thrust out at a right angle 

 to the other toes, which are rather close together. 



Ordinarily possum droppings are in the form of irregular 

 masses about 2 to 2i/2 mcnes long; usually they contain large 

 amounts of fruit hulls and seeds and often some fur and feath- 

 ers. The fur and feathers are more than likely from various 

 creatures that have been killed by some predator other than the 

 possum. 



Distribution. — The opossum is common in Illinois. The sub- 

 species in this state is Didelphis marsttpialis virginiana Kerr. 

 The species has a range that includes an extensive area: all of 

 the eastern United States south of a line drawn from southern 

 New England to southern Minnesota to western Texas; also 

 much of western California. The range extends through Mexico 

 and into South America. 



ORDER INSECTIVORA 

 Moles and Shrews 



The Insectivora are the most primitive of the known living 

 placental mammals; all Illinois mammals except the opossum 

 are placental. Several families of insectivores are recognized. 

 Two of these, the Talpidae or moles and the Soricidae or 

 shrews, are burrowing, thick-furred animals comparable in size 

 to rats and to small mice, respectively. These two families, 

 widespread in the Northern Hemisphere, are represented in 



