LETTERS ON ENTOMOLOGY. 103 
make a property of these cows, which they fight 
for, and endeavour to keep to themselves. If 
strangers attempt to share their treasure, they 
drive them away with as much anger as a farmer 
would show to a thief he found milking his 
cows. Sometimes to rescue them they take them 
in their mouths, and even, if the branch is con- 
veniently situated, inclose it in a tube of earth 
or other materials, and thus confine them in a 
kind of paddock near the nest ! 
The greatest cow-keeper of all is the yellow 
ant, which is met with in our pastures. This 
species, which is not fond of roaming, and likes 
to have every thing within reach, usually collects 
in its nest a large herd of a kind of aphis that 
lives on the roots of grass, and thus, without 
going out, has always a copious supply of food. 
They take as much care of them as of their 
own offspring, and attend the eggs particularly, 
moistening them with their tongues, and giving 
them the advantage of the sun. They are equally 
careful after they are hatched, fighting fiercely 
for them if attacked ; but we shall not be sur- 
prised at thisj when we consider that they pro- 
duce almost their only food, and thus their wealth 
and prosperity depend on the number of their 
cattle. 
