120 THE STUDY OF ANIMAL LIFE 



XI. THE USEFULNESS OF ANIMALS 



Once more we may run through the chief groups 

 of animals which occupy a place upon the British 

 list, and on this occasion we are concerned with 

 their usefulness. 



We start, of course, with the Mammals, the 

 highest group of all, and the Bats, as usual, are 

 placed at the head. These mostly nocturnal 

 creatures live entirely upon insects of various 

 kinds, and perform useful work in ridding us of an 

 enormous quantity of insect life. Beetles and 

 Moths seem particularly relished by Bats, but 

 judging by the manner in which they so quickly 

 secure food, all kinds of insects which populate 

 the air find a warm reception awaiting them from 

 those industrious mammals. 



There are, of course, a number of animals whose 

 value and usefulness can only be judged according 

 to the part they play in preserving the balance of 

 Nature. Thus the Hedgehog is an unmitigated 

 nuisance where game-birds and poultry are found, 

 but elsewhere — and at such times that the eggs 

 of the former are not forthcoming — the Hedgehog 

 exists upon Insects, Worms, Frogs, Toads, Slugs, 

 Snails, and other creatures. 



The Mole in some districts prevents the land 

 from being waterlogged by means of its natural 



