ANIMAL INSTINCT. 
163 
birds likewise appear, and are gone, several of which, 
however, are probably the young of ascertained species. 
And here the little willow-wren is often to be seen : he 
comes in company with his travelling friends, not as a 
partaker of their plunder, appearing never to abandon 
his appetite for insect food : the species may change 
with the season, but still it is animal : he glides about 
our rows of peas, peeps under the leaves of fruit trees 
for aphides and moths, continuing this harmless pursuit 
until the cold mornings of autumn drive him to milder 
regions. All these fruit-eating birds seem to have a 
very discriminating taste, and a decided preference for 
the richest sorts — the sweetest variety of the gooseberry 
or the currant always being selected ; and when they 
are consumed, less saccharine dainties are submitted to: 
but the hedge blackberry of the season our little foreign 
connoisseurs disdain to feed on, leaving it for the hum- 
bler appetited natives— they are away to sunnier regions 
and more grateful food. 
June 14. — I was much pleased this day by detecting 
the stratagems of a common wren to conceal its nest 
from observation. It had formed a hollow space in the 
thatch, on the inside of my cow-shed, in which it had 
placed its nest by the side of a rafter, and finished it 
with its usual neatness ; but lest the orifice of its cell 
should engage attention, it had negligently hung a 
ragged piece of moss on the straw-work, concealing the 
entrance, and apparently proceeding from the rafter; 
and so perfect was the deception, that I should not have 
noticed it, though tolerably observant of such things, 
had not the bird betrayed her secret, and darted out. 
Now from what operative cause did this stratagem pro- 
ceed ? Habit it was not ;• — it seemed like an after- 
thought; — danger was perceived, and the contrivance 
which a contemplative being would have provided, was 
resorted to. The limits of instinct we cannot define : # 
* I know not any definition of what we term “ animal instinct ” more 
comprehensive and accordant with truth than the following, given 
in the Elements of Etymology by Messrs. Kirby and Spence. “ With- 
out pretending to give a logical definition of it, (instinct,) which, 
while we are ignorant of the essence of reason, is impossible, we 
