160 GRAY LADY AND THE BIRDS 
at a tree behind that in which the five Owls were roosting. 
“There is another Owl all by itself that the Jays haven’t 
found out, and it’s all drawn up thin just like my red one.” 
And, following the direction of his finger, the Owl was 
plainly to be seen, but so rigid and motionless that it 
might have been a moss-covered branch stump. 
“We would better go in now,” said Gray Lady, after 
they had watched for a few moments. “The Owls are 
beginning to notice us, and I do not wish them to be driven 
away until I have had a chance to photograph them. 
Leave the box there, Tommy; with all this noise your 
Owl cannot be expected to come out before night.” 
“But if they are good birds, what was the red one doing 
in Tommy’s pigeon-house ?”’ asked Dave. 
“Probably looking for mice or other vermin, or perhaps 
shelter,” said Gray Lady, “for though they sometimes 
eat large game, mice or smaller animals are easier food for 
a tribe of Owls that sometimes grow only six inches high 
and never to a foot in length. I will tell you a way to 
convince yourselves and make sure of what Owls feed 
upon without killing the Owls;” said Gray Lady, as, on 
their way up to the play and work rooms, they went into 
the library to look at some of the mounted birds in one 
of the cases. 
“ As Owls usually swallow their food whole, they take in 
bones, fur, feathers, etc., that they cannot digest; these 
portions are made up into little pellets called ‘Owl balls,’ 
and these are spit up before the real process of digestion 
is begun, and if you search under the trees where owls 
roost, you may often find these pellets for yourselves.” 
“Maybe that is what these things are that I’ve found, for 
