84 
ANIMAL INTELLIGENCE. 
4 some of the most anomalous forms of coleopterous insects 
are those which live solely in the nests of ants.’ Sir 
John Lubbock also, and other observers whom we need 
not wait to cite, mention similar facts. The Rev. Mr. 
White says that altogether 40 distinct species of Coleoptera, 
most of which he has in his own collection, are known 
to inhabit the nests of various species of ants, and to 
occur nowhere else. 
As in all these cases the ants live on amicable terms 
with their guests, and in some cases even bestow labour 
upon them (as in carrying them from one nest to another 
during migration), it is evident that these insects are not 
only tolerated, but fostered by the ants. Moreover, as it 
seems absurd to credit ants with any mere fancy or caprice 
such as that of keeping pets, we can only conclude that 
these insects, like the aphides, are of some use to their 
hosts, although we are not yet in a position to surmise 
what this use can be. 
Habits of Sleep and Cleanliness . — It is probable that 
all species of ants enjoy periods of true sleep alternating 
with those of activity; but actual observations on this 
subject have only been made on two or three species. 
The following is MacCook's account of these habits in the 
harvesting ant of Texas : — 
The .observation upon the ants now before me began at 
8 o’clock; at 11 p.m. the cluster had nearly dissolved, only a 
few being asleep. To illustrate the soundness of this sleep I 
take the quill pen with which I write, and apply the feather 
end of it to an ant who is sleeping upon the soil. She has 
chosen a little oval depression in the surface, and lies with 
abdomen upon the raised edge, and face toward the lamp. Her 
legs are drawn up close to the body. She is perfectly still. 1 
gently draw the feather tip along the body, stroking 4 with the 
fur,’ if I may so say. There is no motion. Again and again 
this action is repeated, the stroke gradually being made heavier, 
although always quite gentle. Still there is no change. The 
strokes are now directed upon the head, with the same result. 
Now the tip is applied to the neck, the point at which the head 
is united to the pro-thorax, with a waving motion intended to 
produce a sensation of tickling. The ant remains motionless. 
After continuing these experiments for several minutes, T 
