222 
ANIMAL CURIOSITIES 
on their night expeditions in search of food, 
are other creatures that progress in regular 
formation. 
A single individual heads the way, and 
behind it march two others side by side. In 
the rear of these three more caterpillars take 
up their position, and behind these again are 
further rows, each successive one comprising 
one more individual than the row in front; 
the entire colony forming a wedge-shaped 
company. Arriving at their feeding ground, 
they ascend the trunks of oak trees in order to 
feed upon the leaves, and when they have 
satisfied their appetite they return to their 
hiding-places in the same marching order as 
before. 
The artilleryman is represented in the Animal 
World by the bombardier beetle (Brachinus 
crepitans), a small species found in certain 
localities of the Southern and South-Eastern 
coasts of England, being especially abundant 
in chalky districts. When irritated the beetle 
ejects an evil-smelling fluid at its foes, the 
liquid having the curious property of vaporizing 
upon contact with the atmosphere and assum¬ 
ing the form of a cloud of smoke, while the 
discharge is accomplished by a slight sound. 
Other beetles are also endowed with the power 
to secrete and eject an acrid fluid as a means 
