OBSERVATIONS ON ANTS. 
79 
queens should exist in one nest. In the nest of Lasius flavus or 
L. niger you seldom find more than one or two ; although on the 
other hand the red Ants usually have about six queens. How- 
ever, to return to the wood Ants. I again visited the nest this 
summer in company with Mr. Bartlett. It was an extremely 
wet day and everything, including ourselves, was soaked with 
rain. One author says that F. rufa closes up the nest on wet days. 
I certainly did not find this the case, because there were hundreds 
of £ minors all over the brambles. 
They were engaged in milking aphides. No 9 9 were found 
that day, but there were plenty of d* c? . The Ants which I took 
that day thrived well in captivity until about a month ago, when 
a small species of mite (acari) invaded the nest. These increased 
so rapidly and covered the Ants to such an extent, that nearly all 
are dead. If I could procure some myrmecophilous beetles (those 
found in Ants' nests) and put them in the artificial nest, they 
would probablv have eaten all the mites. Formica rufa are very 
strong, carrying sticks much heavier than themselves, and they 
carry one another about, seemingly without effort. I made some 
experiments to test the sight of this species. If I passed my hand 
three feet above the nest slowly, the Ants did not see it, but if 
the hand was moved suddenly, they immediately stood on their 
hind legs and looked as formidable as they possibly could. When 
I stamped my foot twelve feet away from the nest, they would all 
jump around in that direction. The small yellow Ant (Lasius 
flavus) can only distinguish objects half an inch away. One day 
I put a small ichneumon flv in a nest of flavus. When the fly 
passed within a half-inch of the Ant, the Ant would immediately 
give chase, but lost the flv when it got more than the half inch 
away. The sight of the cT and 9 Ants are much better developed 
than the $ • The £ in most species have only one pair of 
faceted eyes, but the d* cf and 9 9 have three ocelli in addition to 
the faceted eyes. (The 5 5 of F. rufa has ocelli). 
These ocelli are simple eyes arranged in the form of a A on the 
top of the head. 
The small yellow Ant (Lasius flavus) is one of our commonest 
species. The nests are generally formed by throwing up small 
mounds of earth, or more rarely underneath stones. Two distinct 
sizes of § § are always to be found — called 2 major and 
5 minor. From my own observations the 5 minors appear to 
look after the ova in the nest, while the majors do everything 
else, such as milking aphides, feeding larvae, attending and 
cleaning the queen, building new chambers, defending the nest 
from other Ants, continually removing pupae to different parts of 
the nest, etc. 
A number of aphides can always be found attached to the roots 
of grass, which are growing down through the nest. These 
aphides are, I think, the main support of flavus, because you never 
