d went to spend the next morning with my old friends. The
tree they had chosen was a high oak in an open space in the brush, and
they were building fifteen or twenty feet above the ground--so high that
it was necessary to keep an opera-glass focused on the spot to see what
was going on at their small cup.

As the birds worked, I was filled with forebodings by seeing a pair of
wren-tits on the premises. They went about in the casual indifferent way
sad experience had shown might cover a multitude of evil intentions, and
which made me suspect and resent their presence. How had they found the
poor little gnats? It was not hard to tell. How could they help finding
such talkative fly-abouts? But if birds are in danger from all the
world, including those who should be their comrades and champions, why
should not builders keep as still at the nest as brooding birds, instead
of heedlessly giving information to observers that lurk about taking
notes for future misdeeds? But then, could gnatcatchers keep still
anywhere at any time? No, that was not to be hoped for. I could only
watch the little chatterers from hour to hour and be thankful for every
day that their home was unmolested.

It was interesting to see how the jaunty indifferent gnats would act
when settling down to plain matters of business. Strange to say, they
proved to be the most energetic, tireless, and skillful of builders.
Their floor had been laid--on the branch--before I arrived on the scene,
and they were at work on the walls. The plan seemed to be twofold, to
make the walls compact and strong by using only fine bits of material
and packing them tightly in together; while at the same time they gave
form to the nest and kept it trim and shipshape by moulding inside, and
smoothing the rim and outside with neck and bill. Sometimes the bird
would smooth the brim as a person sharpens a knife on a whetstone, a
stroke one way and then a stroke the other. When the sides were not much
above the floor, one bird came with a bit of material which it proceeded
to drill into the body of the wall. It leaned over and threw its whole
weight on it, almost going head first out of the nest, and had to
flutter its wings to recover itself. The birds usually got inside to
build, but there was a twig beside the nest that served for scaffolding,
and they sometimes stood on that to work at the outside.

At first they seemed to take turns at building, working rapidly and
changing place