What Are Citronella Ants?
Citronella ants (Lasius interjectus) are named for the strong lemon or citronella-like odor they produce when crushed. These ants are yellow to yellowish-brown and relatively large for ants, measuring about 4–5 mm. Workers are rarely seen above ground.
Habitat & Behavior
In North Carolina, citronella ants nest underground, often near foundations, under concrete slabs, and in crawl spaces. They feed primarily on honeydew produced by subterranean aphids and mealybugs that feed on plant roots. They do not forage for food inside homes.
Homeowners most commonly encounter citronella ants when winged reproductives (swarmers) emerge indoors, usually in late winter or early spring. These swarms can be alarming and are sometimes mistaken for termite swarms. The key differences are that citronella ant swarmers are yellow (not dark-colored) and produce a distinct lemon scent.
Prevention & Control
Citronella ants do not cause structural damage and are primarily a nuisance pest. Swarms are temporary and usually last only a day or two. Sealing cracks in foundations and basement floors can prevent indoor emergence. If swarms persist, a professional inspection can identify and treat the nesting site.