Anyone who has ever lived in one of the three mediterranean climates of the world (i.e., Southern California, central Chile, and around the Mediterranean Sea) knows that ants (hormigas) are a constant problem and pestilence. Leave something out on the counter or in the trash, like chicken bones or something sweet, and within an hour an army of ants will be crossing the living room floor, the hallway, the kitchen floor, and in, on, or under countertops. They also search for water during the summer months–or so it seems.

Then at sunset, they all go away.
Mostly, these small black ants are nothing but a nuisance. They rarely bite but they are somewhat unsightly. There are plenty of poisons available to kill them but the best way is simply to keep the kitchen clean and to not have food scraps in other parts of the house.
Chileans believe that ants are the best predictor of upcoming weather. If there are a lot of ants, it means that there will be a lot of rain in the winter. The ants “know” this fact and step up their food gathering processes. If there are few ants, the fall and winter will be dry. Apparently electric companies and other weather-dependent firms actually use ants as part of their forecasting mechanism.
Areas of Chile which are most affected include Santiago, Viña del Mar, Valparaíso, San Antonio, Rancagua, La Serena, and every smaller city in between. In other words, the 4th Región, the 5th Región, the 6th Región, and the the Región Metropolitana.
If you live in these areas or plan to live in them, be prepared to face the ants at some point. For they shall surely come!