Ants in Home Lawns

Winged ants are frequently confused with swarming termites. Ants can be easily distinguished from termites by the following characteristics:

• ants have elbowed antennae while those of termites are straight and beadlike;
• front wings of ants are larger in size than the rear wings while those of termites are all equal in size;
• the waist of ants are thin and appear to be constricted while those of termites are broad and not constricted; 
• wings of ants are usually transparent or brownish while those of termites are milky-white.

Description

Little Black Ant

Workers of this species are 1/10-1/8 inch in length with soft jet-black bodies. These ants are found primarily in soil and rotting wood. They feed on a wide variety of food sources.

The Pavement Ant

These ants are slow, sluggish, short-legged, and usually nest under pavements and foundations. They are 1/12-1/4 inch in length and brownish-black. They feed on a wide variety of food sources (seeds, grease, animal food).

Cornfield Ant

These ants are usually found nesting in open places in the soil or in rotten wood. They are 1/8-1/4 inch in length, robust, soft-bodied, and light to dark brown. The body, when crushed, has an acid (formic) odor. These ants are found feeding on seeds, and often are associated with aphids and mealybugs which are excreting honeydew.

Larger Yellow Ant

These ants are 1/10-1/8 inch in length and yellow. When crushed they give off a characteristic lemon-verbena odor. They are common soil inhabiting species which tend mealybugs and aphids on the roots of plants.

Life History

Ants form colonies or nests where queens remain. Most ant species have only one queen per nest; she lays the eggs needed to maintain or increase the colony. Queens may live from 1-15 years and produce many thousands of eggs.

Larvae, or maggot-like grubs, hatch from the eggs. They are transparent white, soft-bodied, and legless. These larvae, along with the queen, are fed by the worker ants (foragers). Larvae pass through several molts before pupation and adulthood are reached. The majority of these develop into workers; a few develop into winged males and females which are the kings and queens of the ant colony. At certain times during the year (usually early spring and late summer), varying with the species, these winged ants leave the nest and swarm. Females and males mate and the males die soon after. The mated female (queen) flies to an attractive nesting site, tears off her wings, and encloses herself in a small excavation in the soil, and lays eggs. She feeds and cares for the first generation of progeny until they are mature adults. After that they and succeeding generations care for her. She remains in the nest and continues to produce eggs the remainder of her life.

Damage

Ants seldom cause serious damage to home lawns. They may cause minor damage to the turf by loosening the soil and constructing small mounds in the nesting areas. Ants also feed on honeydew (sticky sugary substance) excreted by aphids, mealybugs, and soft scales. Homeowners may become alarmed when ants swarm during spring and late summer because they associate swarming insects with termites. However, if they examine specimens for the above differentiating characters, confusion should be eliminated. Respect these small insects since they do bite and some can also sting. Many ants are considered beneficial because they are scavengers and predators on certain harmful insects.

Control

Home Lawn Control Only

The secret of success in controlling an ant infestation is to locate and destroy the nest, including the queen and her young. Attempt to trace the ants' line of march from the food source to the approximate nest location. There are several registered insecticides that can be applied on home lawns. Careful spot treatments of ant hills with a registered control material will help reduce ant populations. If the entire lawn is treated, water the lawn immediately to wash the registered insecticide into the soil. Do not allow children to play on the grass until the chemical has been washed in and the grass has dried. An alternative in preventing any of these ants from invading your home is to apply a barrier treatment with a registered formulation of an insecticide. Follow label directions carefully for each treatment.

Authored by: Gregory A. Hoover, Extension Entomologist

Last updated February 1992