SB 
818 
C578 No. 34, SECOND SERIES, REVISE. Issued June 12, 1907. 
ENT 
ited States Department of Agriculture, 
BUREAU OF ENTOMOLOGY, 
L. O. HOWARD, Entomologist and Chief of Bureau. 
HOUSE ANTS. 
Monomorium pharaonis et al. 
3y C. L. MARLATT, 
Entomologist and Acting Chief in Absence of Chief. 
There are a number of species of ants often occurring in houses, the 
more important of which are common to both hemispheres and are 
probably of Old World origin. One of these, the little red ant (Mono- 
morium pharaonis L.), has become thoroughly domesticated and passes 
its entire existence in houses, having its nests in the walls or beneath 
the flooring and usu- 
ally forming its new 
colonies in similar fa- 
vorable situations. 
Two other ants are very 
common nuisances in 
houses, namely, the 
little black ant (Mo- 
nomorium  minutum 
Mayr) and the pave- 
ment ant of the At- 
lantic seaboard ( Tet- 
ramorium  caspitum 
L.). None of these 
ants is so destructive Fig. 1.—The red ant (Monomorium pharaonis): a, female; 
b, worker. Enlarged (from Riley). 
to household effects or 
supplies as it is annoying from the mere fact of its presence and its 
faculty of ‘getting into”’ articles of food, particularly sugar, sirups, 
and other sweets. Having once gained access to stores of this sort, the 
news of the discovery is at once conveyed to the colony, and in an 
incredibly short time the premises are swarming with these unwelcome 
visitors. 
HABITS AND LIFE HISTORY. 
In habits and life history these ants are all much alike and, in com- 
mon with other social insects, present that most complex and interest- 
ing phase of communal life, with its accompanying division of labor 
and diversity of forms of individuals, all working together in the most 
perfect harmony and accord. The specimens ordinarily seen in houses 
are all neuters, or workers. In the colony itself, if it be discovered and 
opened, will be found also the larger wingless females and, at the 
proper season, the winged males and females. During most of the 
year, however, the colony consists almost exclusively of workers, with 
one or more perfect wingless females. Winged males and females are 
