t. Not a stick or a wisp of hay or a
feather to mark the place! And as she sat there quietly, a queer thing
happened. She disappeared from sight. As long as she didn't move, she
couldn't be seen. Her dappled feathers didn't look like a bird. They
looked like the light and dark of the pebbles of the flat roof. Ah, so
_that_ was the one thing more that was necessary for her home, besides
sunshine and peace and good hunting. It must be where she could sit and
not show; where she could hide by just looking like what was near her,
like a sand-colored grasshopper on the sand in the sun,[2] or a
walking-stick on a twig,[2] or a butterfly on the bark of a tree.[2]

Yes, Mis's mate knew, in some natural wise way of her own, the secret of
making use of what we call her "protective coloration." This is one of
the very most important secrets Mother Nature has given her children,
and many use it--not birds alone, but beasts and insects also. They use
it in their own wild way and think nothing about it. We say that it is
their instinct that leads them to choose places where they cannot easily
be seen. If you do not understand exactly what instinct is, do not feel
worried, for there are some things about that secret of Mother Nature
that even the wisest men in the world have not explained. But this we do
know, that when her instincts led Mother Nomer to choose the pebbly roof
as a background for her mottled feathers, she did just naturally very
much the same thing that the soldiers in the world-war did when they
made use of great guns painted to look like things they were not, and
ships painted to look like the waves beneath them and the clouds in the
sky above. Only, the soldiers did not use their protective coloration
naturally and by instinct. They did this by taking thought; and very
proud they felt, too, of being able to do this by hard study. They
talked about it a great deal and the French taught the world a new word,
_camouflage_, to call it by. And their war-time camouflage _was_
wonderful, even though it was only a clumsy imitation of what Mother
Nature did when the feathers of Mother Nomer were made to grow dappled
like little blotches of light and dark; or, to put it the other way
about, when the bird was led, by her instinct, to choose for the
nesting-time a place where she did not show.

Of course, it was not just the gravel on the flat roof that would match
her feathers; for there isn't a house in the land that is nearl