In pools where you stoop to drink you can see the little cylin¬ 
drical houses. Above is the mature caddis 
The caddis, you will notice, drags his home-made house along 
the bottom. Every day is moving day to him 
BEING THE STORY OF THE CADDIS FLY, THAT IS ITS OWN ARCHITECT AND CONTRACTOR—THE CON¬ 
STRUCTION OF ITS HOUSE—WHERE THE HOME IS LOCATED—THE LANDLORD PROBLEM SOLVED 
S. H. Chubb 
The American Museum of Natural History 
N EARLY everyone, who is in the habit of drinking at 
a spring in the primitive fashion with neither cup 
nor glass, has discovered those curious little cylinders, 
crawling, or rather being dragged, about on the bottom by 
their occupants and builders, the caddis worms, or, to 
speak more correctly, the larvae of the caddis fly. This 
little creature has solved the landlord problem. The 
monthly demand comes not to his door! 
While most of these structures are of the - —- 
cylindrical school of architecture, there is a 
great diversity of treatment displayed by the 
various species, although the available mate¬ 
rial has much to do with the appearance of 
the finished dwelling. Almost anything 
which can be found at the bottom of streams 
and ponds may be used. Bits of sticks, tiny 
seeds, pieces of leaves, grains 
of sand or small stones are -;^ r , 
gathered and fastened to- 4 ! 
gether with silk-like threads : j 
of the builder’s own make. 
The case is also nicely lined || 
with this material, which is 
spun very much as a silkworm 
or caterpillar spins its cocoon. 
The separate threads can be 
distinguished only when mag¬ 
nified about ten times. 
The larva is a soft-bodied j 
little grub, too tempting to Jj 
escape the sharp eyes of small L 
fishes, were it not for his 
hermit protrude at the open end of the cylinder and 
he will crawl about leisurely, dragging his home with him. 
At the extreme posterior end of the body there are two 
hooks with which he hold,s tenaciously to the inside of 
the case, and will refuse to be extracted even at peril of 
'pile variety 6 shown ' Je ‘ n §' pulled in two. An attack from the rear, however, 
opposite is so unusual an experience that it takes him quite by 
surprise. Should you wish to examine him 
——---• ~—• more thoroughly, take a pine-needle or fine 
j| grass stem and thrust it gently into the very 
small opening at the posterior end of the 
case, and the probability is lie will make a 
hasty advance out the other end, but will 
soon dive in again head first and then turn 
round at his leisure. 
On one occasion, having a number of cad- 
§§ dis larvae under close observa- 
if 
strange covering. When there 
seems to be no danger near, 
the head and legs of the 
While most of the structures are of the cylindrical school of architecture, a diversity 
of treatments is displayed. When there is no danger, the head and legs of the 
grub come out and he walks around dragging his house behind him. Pictures 
highly magnified 
tion, I found that by some 
chance one caddis had been 
divested of his covering. In¬ 
stead of adopting the usual 
course of diligently setting to 
work to repair the loss, this 
individual became alarmed and 
quite demoralized, broke into 
the back door of one of his 
neighbors, driving him out 
the front way. The rightful 
owner turned round and faced 
the enemy, but could not pre¬ 
vail. After some manoeuv¬ 
ring he discovered the breach 
in the rear and drove out the 
intruder, who then repeated 
his strategic move. This most 
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