About Ants
Ants are social insects that live in colonies ranging from dozens to millions of individuals. They are among the most common household pests and are frequently found foraging for food or establishing nests in soil, wood, or structural voids. Their ability to form large, resilient colonies makes them persistent invaders in residential and commercial environments.
Physical Characteristics of Ants
Ants vary significantly in size, color, and morphology depending on the species. Most ants are between 1/16” and 1/2” long and exhibit:
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A segmented body consisting of head, thorax, and abdomen
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Elbowed antennae
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Six legs
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A narrow waist (petiole) that may have one or two nodes
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Mandibles used for cutting, carrying, and defensive purposes
Reproductive ants (alates) are winged and emerge seasonally to mate. After mating, queens lose their wings and begin forming new colonies.
Ant Appearance in California
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Argentine ants, the most widespread species in California homes, form large, uniform lines of small brown workers.
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Odorous house ants are dark brown to black and emit a distinct smell when crushed.
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Carpenter ants are larger ants, often black or red-and-black, and may be seen near wood structures.
These species dominate residential settings throughout much of the state.
Where Ants Nest and Travel
Ant nests vary depending on species and may be found in:
- Soil
- Mulch beds
- Beneath rocks or pavement
- Rotting or water-damaged wood
- Wall voids
- Baseboards and insulation
- Tree roots or stumps
Ants typically travel along established trails between nesting sites and food sources.
Common Nesting Sites in California
- Moist soil and irrigated areas, such as garden beds and lawns
- Structural voids, especially in older coastal homes
- Foundation cracks, which provide entry to indoor nesting areas
- Landscaping features, including decorative stones, railroad ties, and retaining walls
These nesting environments are especially common in suburban and coastal California.
What Are the Risks of Ants?
While ants do not transmit diseases at the same level as some other pests, they can still pose risks, including:
- Contamination of food and surfaces
- Damage to wood in the case of carpenter ants
- Painful bites or stings for certain species
- Large-scale infestations, due to rapid colony expansion
Some ants leave persistent pheromone trails that encourage repeated foraging in the same areas.
Ant-Related Concerns in California
- The statewide prevalence of Argentine ants leads to frequent kitchen and pantry infestations.
- Carpenter ants may contribute to structural damage, especially where moisture is present.
- Fire ants, present in parts of Southern California, can deliver painful stings.
- Local climate patterns—especially drought—cause ants to enter homes seeking water sources.
These issues make ants a significant nuisance in residential environments throughout the state.