406 USEFUL BIRDS. 
continue their nefarious work elsewhere. Millais confidently 
advances the theory that a few individual birds do the mis- 
chief for which perhaps the whole race is blamed. He be- 
lieves that the individual criminal among birds does his work 
stealthily, and so is seldom observed; that his family is fed 
on the results of his rapacity; and that the young acquire 
similar tastes and habits, which in time may spread from 
family to family and from one community to another. He 
states that years ago the Rooks of southern England were 
practically innocent of stealing eggs or young birds, though 
their cousins in the north were nest-robbers even then. He 
says that now there is hardly a community of Rooks in the 
south of England that does not contain individuals with the 
nest-robbing habit. The view that certain depraved indi- 
viduals among birds and mammals are responsible for most 
of the unusual depredations on other birds and mammals is 
held by many observers. The Marsh Hawk and the Red- 
shouldered Hawk are among the most useful of all Hawks ; 
but I have known individuals of both these species to be 
destructive to birds or young poultry. If such individuals ~ 
can be shot, it will be a decided benefit to all concerned. 
Where Cooper’s and Sharp-shinned Hawks cannot be shot, 
they may be caught by setting steel traps in their nests. 
It is quite probable that some Crows do not habitually 
steal the eggs and young of other birds. In fall, winter, 
and early spring we may welcome Crows about our farm 
buildings. They may do much good in the fields in summer, 
but, as a measure of safety, they should be kept as far away 
from small breeding birds as possible. Poison will kill some 
and drive the rest away; but exposing poison in this way is 
illegal, and there is great danger of poisoning useful birds. 
Egg-eating Crows may be trapped by exposing an egg on 
the ground in such a way that the Crow must step into a 
concealed trap to get the egg. After two or three have 
been caught in this way, the others will avoid the place. 
Our laws which deny protection to the Crow are wise, for 
it is one of those species which, though at times most useful, 
may become a pest if not held severely in check. 
Watch the Jays, and shoot every one that is found dis- 
