126 THE POPULAR SCIENCE MONTHLY 
to reach the big carpenter ants (Camponotus herculeanus), which had 
extended their galleries up into the tree’s heart, and some of which 
were already entrapped in the exuding pitch. Now one of the chief 
points of interest in this case was that the ant-borings were few, and 
the tree itself so large and solid that it would seem to be impossible 
for any bird to detect their presence by sounding with the bill. On the 
opposite side at the base, a long ant-hole was plainly seen, and at this 
point the observations of the woodpecker had evidently begun. A. few 
feet above this opening it had attacked the harder wood in -three 
different places, but desisted after making wells a few inches deep. 
The woodpecker then went up seven feet, where the wood was pre- 
sumably softer, and made the drilling, which led to success. With 
these facts only known, this might appear like a case of reasoning by 
analogy, but there is still one sense unaccounted for, that of hearing, 
for the olfactory sense must be ruled out. It is possible, or even 
highly probable that such birds either instinctively or habitually follow 
the sounds in wood—sounds of wood-borers at work—and unless it 
could be shown that the boring of carpenter ants cannot be heard 
through five inches of solid wood, I should be inclined to accept this 
view. 
This case suggests another practise of woodpeckers, the interpreta- 
tion of which is clear. The president of a large university recently 
compared the futile efforts of certain reformers with these of a flicker 
which was seen to be repeatedly engaged in the vain attempt to “ drill 
a hole through a copper gutter.” The comparison may be apt to point 
a moral, but is a trifle unfair to both the instincts and intelligence of a 
useful bird, which will drum on any resonator, either to call its mates 
or for the pleasure of the sound, and by habit will come to the same 
place daily for more than a week, as in a case which we recently noticed. 
In this instance the resonant body was the roof of a bird house, one 
shingle thick, to pierce which, had that been its object, one or two blows 
of its strong bill would have sufficed. 
II. INTELLIGENCE IN Youne Birps 
The dawn of intelligence in young birds is seen, as we have earlier 
shown, through the inhibition of the food-response by association— 
association with the parent, the nest or the vibration imparted to the 
tree by the touch of the parental foot. 
For the first twenty-four hours, or longer, the altricious nestling 
behaves like a mechanical toy, and in relation to the food-response is a 
well-nigh perfect reaction-machine. It responds to every kind of a 
tactile or auditory stimulus, and within the limits of fatigue its 
1 See also “ The Relation of Instinct to Intelligence in Birds,” Science, N.S, 
Vol. XXVII., 1908. 
