I have very few black ants in my house; here's why. Photo 1 shows the soil around my foundation covered with hundreds of these inverted cones/pits. The quarter is to show scale. These are the traps of the Ant Lion who burrows into the soil and then flicks his head to throw the soil up and out. The sides of the pit are constructed at the "angle of repose" which is the steepest you can pile dirt up, without it collapsing in on itself. A hapless and falls into the pit and as it tries to scramble out, the sides collapse and the ant falls to the bottom of the pit.

Photo 2 shows what awaits the ant in the soil underneath the bottom of the pit. The Ant Lion is about the size of a big sunflower seed with some serious pincers that reach up through the dirt, grabbing the ant and pulling it underground for a meal. Does anyone remember in "Star Wars Return of the Jedi" the pit in the desert with the Sarlac monster waiting for a prisoner of Jobba the Hut to be thrown in?

Needles to say, I go through great pains not to disturb what I refer to as the "ant mine field" hidden behind my shrubs.