Pavement ants (Tetramorium immigrans) are very small ants that are encountered frequently by Maine homeowners. They enter homes through cracks (especially cracks in foundations and concrete slabs), and they like to nest in the soil under the floors of homes or offices, or under sidewalks, driveways, stones, logs, etc. They feed on a great variety of food sources, including sugary items, meats, grains such as breads and crackers, food garbage, other insects, pollen, pet food and nuts, to name but a few.
Additional Information: Pavement Ants (Univ. of Minnesota Extension)