One of the delights of the season is sharing a holiday brunch with family and friends. In my home this includes six-legged friends as well as those with two. After a busy week of baking and cooking, my home has been invaded with legions of small, dark brown ants known as odorous house ants. The unusually warm weather outdoors and an abundance of sweet foods indoors have much to do with this holiday visit.
In a matter of minutes workers find a drop of syrup.
House ants are usually most abundant indoors in the spring and early summer. After spending the chilly winter months in a state of relative inactivity, worker ants begin to forage for sugars, proteins, and fats outdoors as the temperature rise in spring. In the wild these foods come from sucking insects such as aphids and scales, small insects, and plant parts such as nectar and seeds. When ants locate a rich source of food such as the sweet honeydew produced by a colony of scale insects, they establish a chemical trail that leads other workers from the nest to the bounty.
It doesn't take long for many workers to follow the pheromone trail to food.
Their search for food brings them into our homes. A small pile of sugar on the counter, a pet dish on the floor, or a leaky jar of pancake syrup in the pantry, are often enough to initiate a full scale invasion by searching workers. During the unusually warm weather we have enjoyed over the holidays, odorous house ants have stepped up their foraging activities from a trickle to a rampage. The aftermath of my holiday brunch included a few drops of sticky pancake syrup on the counter. Within a matter of minutes the syrup was discovered and in less than half an hour about two dozen eager workers were recruited to the drop. A two-directional ant freeway was established from the drop, along the edge of the counter, and down a wall where the trail disappeared into a small crack at the junction of the cabinet and the wall. While the odorous house ants brought much holiday cheer to my household, not everyone finds their antics quite so amusing.
Workers tank up on a sweet attractant containing an insecticide that will be taken to the colony and kill other workers and the queens.
If you find ants and their telltale trails on your counters or along the baseboards, try to follow the trail back to the point of entry into your home. In my home this is small crack were the cabinet joins the exterior wall. To foil their feeding fun, first eliminate as many sources of food as you can find. Clean the counters, mop up drips, and get the pet food off the floor. Be sure that no syrups or sweets are spilled or leaking in your cupboards. Ant trails on the counter or floor can be disrupted by spraying them with household cleansers or other solutions. You can buy ant traps or purchase tubes of liquid or gelatin ant baits. Place ant traps or baits at locations indicated on the label. I usually place one near the point of entry to my home. These traps and baits contain a lure that attracts ants searching for sweets or fatty foods. The lure has a slow acting poison that the workers carry back to the colony. They feed the deadly meal to the queens and their nest mates and, voilà, the royals are gone and the colony with them. Be sure that the trap or lure is attracting ants. I tested several kinds during this holiday season and found that liquid bait containing a sweet lure attracted a far greater number of house ants than other types of traps. If you buy any product containing an insecticide, be certain that it specifies that it may be used for ants and always follow the instructions on the label precisely. Many species of ants enter our homes at different times of the year. Large black ants in the home, especially ones with wings, may be carpenter ants and a sign of a more serious problem. For these, you may want to seek confirmation from your local cooperative extension service or a professional.
References:
For more information on house ants and their management please visit the following web sites:
http://www.ipm.ucdavis.edu/TOOLS/ANTKEY/odorous.html
http://www.agnr.umd.edu/users/hgic/pubs/online/ants.pdf
http://lancaster.unl.edu/enviro/ants/OdorousAnt.htm