What's that smell?
It's Odorous House Ants
When you have a sudden invasion of your house by hundreds of small to medium sized (1/16" – 1/8" long), blackish ants, especially if this begins just after a heavy rain, you may wonder where they all came from. These are very likely to be Odorous House Ants. Although they sometimes establish a nest in a wall void or similar location within a house, their main nest is usually outdoors, in the ground near a shrub, or under a thick layer of mulch. Following their trails to where they disappear into a crack under a door, or through an opening to the outside, may help confirm that identification. If you crush one or two of these ants and they smell like the odor of rotting coconut, this will further support that they are probably Odorous House Ants. Their colonies vary greatly in size, with 300 to 300,000 workers, and may include many queens. These ants will feed on a variety of foods, but they generally prefer sweets. Both workers and reproductives may live for several years. Workers from different colonies are not hostile toward each other, and may routinely move along the same foraging trails.