294 USEFUL BIRDS. 
and two per cent. of vegetable matter, which is made up of 
bits of plants taken accidentally with the insects. Half of 
the animal food is grasshoppers and beetles; the remainder 
mostly caterpillars, bugs, and spiders. 
The Wren does not range far from its nest, and when that 
is near the garden it gets a large part of its food there. In 
Medford we succeeded in getting two families of Wrens to 
nest in boxes, one on the house, the other in an apple tree. 
The entrances to these boxes were round holes a little less 
than an inch in diameter. The Sparrows could not get in, 
and so the Wrens were unmolested. 
The only injurious habit of the Wrens seems to be their 
mischievous conduct in breaking and even eating the eggs 
in the nests of other birds.. This habit seems to be common 
to individuals of this and other species of Wren, but it has 
been recorded so seldom in Massachusetts that no one need 
hesitate to put up boxes for them. Unless something can 
be done to provide for their increase, they are likely to 
disappear from the State. 
SPARROWS. 
Some members of this group, particularly the Finches and 
Grosbeaks, have been included in previous pages, among the 
birds of orchard and woodland (see p. 215); the remaining 
common species are mainly birds of the field that nest on 
or near the ground, and get most of their food in fields, 
gardens, or pastures. 
Although they are all seed-eating birds, they live largely 
on insects during spring and early summer, and their young 
are fed mainly on suchfood. In falland winter Sparrows feed 
on the seeds of grains, grasses, and weeds, although they 
are not then averse to insect food when they can find it. 
Dr. Judd, in his important paper, “The Relation of Spar- 
rows to Agriculture,” states that the value of these birds to 
the agriculturist is greater “than that of any other group 
whose economic status has thus far been investigated.” He 
says, nevertheless, that the native Sparrows contrast markedly 
in this respect with the introduced “ English” Sparrow, which 
isa pest. The great bulk of the food of Sparrows consists 
