HOUSE ANTS: KINDS AND METHODS OF CONTROL. 9 
(fig. 1), is essentially a lawn or meadow ant, and its entrance into 
houses is due to chance or accident. Its small nests, with the opening 
surrounded by its protecting wall of fine grains of soil, can be fre- 
quently noted in lawns, and if these nests are opened the colonies 
will be found to consist of workers, with one or more much larger 
gravid females. When these or other lawn ants gain access to houses, 
attracted by food supplies, the nuisance can often be eliminated by 
tracing them back to their outdoor colony and destroying the latter, 
as hereinafter described. 
Perhaps the most abundant and widespread lawn or garden ant 
is a small yellowish-brown species which may be given the common 
name of the American lawn ant. Its crater nests are exceptionally 
abundant throughout the Northern States, and not infrequently a 
dozen or more nests may occur on a square yard of lawn surface. 
In addition to the fact that it occasionally gains entrance to houses 
and becomes annoying as a depredator on larder supplies, it is a 
lawn and garden pest of some importance; and, furthermore, has the 
reputation of hoarding over winter the eggs of aphids and col- 
onizing the young aphids in the spring on their host plants, thus 
becoming a very important factor in increasing the damage to 
garden and field crops by these injurious insects. In the case of 
lawns and meadows, aside from the harboring of injurious aphids, 
direct injury from this ant is probably negligible, or is offset by the 
actual benefit which may result from the bringing up of its little cra- 
ters of sand and earth to form a sort of top dressing or soil mulch. 
The other two native garden and lawn ants have similar habits. 
In this same class of outdoor ants which may occasionally find 
entrance into houses. should be included the common European 
meadow ant,? one of the few Old-World ants of temperate regions 
which has been brought to America. This ant has readily accommo- 
dated itself to conditions of urban existence in the eastern United 
States, and its colonies occur in lawns and often under pavements, or 
beneath flagging or stones in yards. These colonies are often large 
and may frequently be uncovered in masses of a quart or more, on 
turning over stones in yards or lifting flagging in paths. 
HABITS AND LIFE HISTORY OF HOUSE ANTS. 
In habits and life history these ants are all much alike and, in 
common with other social insects, present that most complex and 
interesting phase of communal life, with its accompanying divi- 
sion of labor and diversity of forms of individuals, all working to- 
gether in the most perfect harmony and accord. The ants ordinarily- 
seen in houses are neuters or workers. In the colony itself, if it be dis- 
covered and opened, will be found also the larger wingless females and, 
1 Lasius niger L. var. americanus Emery. 
2Tetramorium caespitum L, 
