392 USEFUL BIRDS. 
and less likely to be caught by cats, Crows, or snakes than 
they would be if reared in a box from which they could get 
out before they were fully fledged. 
For practical utility a nesting box should not only provide 
the birds with an acceptable nesting site, but it should also 
furnish them perfect protection from the elements and their 
larger enemies, and should be so made 
that the interior can be quickly examined 
and the contents removed, if necessary. 
The roof or cover should be hinged or 
made to take off, so that if any young 
bird fails to get out it may be liber- 
ated ; while if undesirable tenants, such 
as mice, Sparrows, or squirrels, get in, 
they may be ousted. The box is much 
more satisfactory as a protective device 
if made so strong that neither Wood- 
peckers nor squirrels can easily enlarge 
the entrance sufficiently to allow ene- ° 
mies of the occupants to get in. All 
these essentials may be secured without 
expense by using worn-out or discarded 
utensils or receptacles. 
An empty tomato can may in a few 
Fig. 167.—Shinglebox, minutes be made into a nesting box by 
iceneaacsias slitting the tin of the opened end twice 
and turning down the piece between the slits, thereby mak- 
ing a hole not over an inch wide and high. It can be put up 
very quickly by placing the bottom of the can against a tree 
trunk and nailing it there with two wire nails driven diago- 
nally through the edge, or by fastening it to a piece of board 
or a pole, which can be attached to a tree or building. The 
cover may be kept in place by pinching the mouth of the can 
a little. The tomato can box is shown in Plate XLVIII. 
This is a practical box for Wrens, and it may be used by 
Bluebirds if the entrance is made larger. 
When holes are cut through tin, the sharp edges round the 
opening should be turned over with a pair of pliers, that the 
birds may not injure themselves in going in or out. Rusty 
