Which ants are characterized by their small size and ability to infest structures?

Pavement ants are particularly noted for their small size and propensity to invade structures, making them a common concern for homeowners and pest control professionals. These ants typically measure around 2.5 to 4 mm in length and are often found nesting in pavement cracks, under stones, and even within building foundations. Their ability to thrive in urban environments enables them to find entry points into homes and other buildings, where they may forage for food, leading to infestations.

The other options do not fit the description of small ants that infest structures. Firebrats are not ants but rather a type of insect related to silverfish, and they prefer warm, moist environments. Honey bees, while beneficial for pollination, are much larger and typically do not infest structures in the same way as ants do. Giant European hornets are also larger and are more known for their aggressive behavior rather than for nesting in structures like pavement ants do. Therefore, the characteristics of pavement ants align perfectly with the question regarding small ants that can infest structures.