Odorous house ants get their name from the unpleasant, rotten-coconut odor they release when crushed. They are persistent foragers, forming long trails from an outdoor or wall-void nest to any available food source, with a particular fondness for sugary and sweet spills.
Colonies can be large and split into multiple satellite nests, which makes do-it-yourself sprays largely ineffective — killing visible workers does not stop the colony from rebuilding. Sealing entry points, cleaning up food residue promptly, and trimming vegetation that touches the home reduce the chances of a trail forming in the first place.