280 ENTOMOLOGY 
Diptera and Coleoptera derive their food from dead animal 
matter. The aquatic families Dytiscidee and Gyrinidz are 
largely scavengers. Among terrestrial forms, Silphide feed 
on dead animals of all kinds; the burying beetles (Necroph- 
orus), working in pairs, undermine and bury the bodies of 
birds, frogs and other small animals, and lay their eggs in the 
carcasses ; Histeridze and Staphylinide are carrion beetles, and 
Dermestidz attack dried animal matter of almost, every de- 
scription, their depredations upon furs, feathers, museum: 
specimens, etc., being familiar to all. Ants are famous as 
scavengers, destroying decaying organic matter in immense 
quantities, particularly in the tropics. Many Scarabzeidze feed 
upon excrementitious matter, for example the * tumble-bugs,”’ 
which are frequently seen in pairs, laboriously rolling along or 
burying a large ball of dung, which is to serve as food for the 
larva. 
Insects as Food for Vertebrates.—Lizards, frogs and 
toads are insectivorous, especially toads. The American toad 
feeds chiefly upon insects, which form 77 per cent. of its food 
for the season, the remainder consisting of myriopods, spiders, 
crustacea, molluscs and worms, according to the observations 
of A. H. Kirkland, who states that Lepidoptera form 28 per 
cent. of the total insect food, Coleoptera 27, Hymenoptera 19 
and Orthoptera 3 per cent. The toad does not capture dead 
or motionless insects but uses its extensile sticky tongue to lick 
In moving insects or other prey, which it captures with sur- 
prising speed and precision. In the cities one often sees many 
toads under an arc-hght engaged in catching insects that fall 
anywhere near them. ‘Though its diet is varied and some- 
what indiscriminate, the toad consumes such a large propor- 
tion of noxious insects, such as May beetles and cutworms, 
that it is unquestionably of service to man. 
Moies are entirely insectivorous and destroy large numbers 
of white grubs and caterpillars; field mice and prairie squirrels 
eat many insects, especially grasshoppers, and the skunk rey- 
els in these insects, though it eats beetles frequently, as does 
