For these swarming, stinging insects it’s the aroma of home sweet home You and a fire ant have something in common: you can both smell dirt, and, odds are, you both like it. Although most humans agree that fresh dirt smells sweet, that is not a view universally shared. Fruit flies hate the smell, apparently because it signals spoiled food. On the other hand, mosquitoes like dirt smell and use it as a cue for egg laying. And as I wrote last spring, tiny arthropods called springtails think dirt not only smells great, it’s the smell of steak night at the Sizzler. The reason, as I wrote here earlier this year, is that dirt doesn’t smell like dirt. It smells like bacteria — actinobacteria, to be precise. These bacteria generate the odors we think of as characteristic of dirt to ring the dinner bell for springtails to come eat and disperse their spores. Why fire ants think dirt smells good, and how we even came to investigate this unorthodox question, is a different story.