TITMICE AND THRUSHES. 79 
also seem that, when in want of fresh air, the little 
creatures, by a simultaneous exertion, expand the 
sides of the nest to the utmost possible degree, thus 
causing the atmosphere from without to make its 
way into every part of the interior. In a very full 
nest this movement will take place ten times or more 
in an hour. 
THE pretty little Yellow Wagtail, which we may 
take as a type of the family to which it belongs, is 
another great insect-destroyer, and is particularly 
fond of the flies, &c., which torment cattle so greatly 
during the summer months. What the nightjar is 
by night, in fact, the yellow wagtail is by day, 
both birds preserving the cattle from an immense 
amount of unnecessary annoyance and suffering. 
Unlike many of its race, the yellow wagtail cares 
little for the neighbourhood of water, and may often 
be seen in meadows far distant from any stream, 
hopping along with its peculiar, jerky movement, and 
ever and anon picking up an insect from among the 
roots of the grass. Even upon a dusty road the 
energetic little bird will carry on its researches, and 
the frequency with which it delivers its quick, 
pecking strokes forms sufficient evidence of the 
number of its victims. 
PAssING to the family of the Thrushes, we come to 
the Redwing, a winter visitor only, but one whose 
services are yet of a highly serviceable character, 
For during its entire stay in this country it is working 
G 
