82 LETTERS ON ENTOMOLOGY. 
their hold, and tumble down ; but they soon 
recover themselves, and bite every thing they 
run against, when it is prudent to keep out of 
their way, for they make their fanged jaws meet 
at the very first stroke, and will not let go though 
pulled limb from limb. 
If on the first attack you give them no further 
interruption, in less than half an hour they re- 
turn into the nest, and the labourers hasten in all 
directions towards the breach, every one carry- 
ing in his mouth a lump of mortar, half as big 
as his body, which he sticks on the breach ; and 
this is done with so much regularity and despatch, 
that although thousands or millions are employed, 
they never appear to interrupt each other. 
While the labourers are thus employed, almost 
all the soldiers retire, except here and there one, 
who saunters about among the workers, but never 
assists in the work. One in particular places 
himself close to the wall which they are building, 
and turning himself leisurely on all sides, as if 
to survey the proceedings, appears to act as an 
overseer of the works. 
Every now and then, at the interval of a 
minute or two, by lifting up his head and striking 
with his forceps upon the wall of the nest, he makes 
a particular noise, which is answered by a loud 
