Is it Normal to Have Ants on a Deck?

Types of Ants

• Of the hundreds of different species of ants, some are more likely to be marching across the backyard deck in search of food than others. Carpenter ants don't eat wood as their name might suggest, but simply make their nests out of wood while workers bring back sweets for the food supply.

  Pavement ants are small black ants that are attracted to a variety of foods, some of which -- particularly pet foods -- are sitting out on decks. Pharaoh ants are attracted to both fatty and sweet foods and these versatile pests often nest outside in sheltered areas. Odorous house ants are so named for the smell they release when crushed and a variety of foods will draw them from their outdoor nests.

Nest Locations

• The ants that are marching across the deck are worker ants on the search for food to take back to the colony. There are two classes of workers -- minor and major -- but both of these groups typically follow set patterns and navigate by scent trails. These trails lead from the nest to known food sources, making it easier for ants to find their way to food and back. It also makes it easier for those being invaded to find their nests.

  Some ants -- such as pavement ants -- will build nests out in the open among the cracks in sidewalks and driveways. Others, like the odorous house ant and the pharaoh ant, can be found in debris outside. If an ant colony decides to build a nest near or even under the house, there will most likely be foraging parties sent out to find whatever easy food they can.

Control

• If you can follow trails back to the nest, spray pesticide can be effective in eliminating the nest. Bait traps can also be effective; set the bait traps out on the deck near the ant trails and the workers will pick up the poison and return it to the nest. Either of these methods is more effective than just spraying the workers found on the deck, as the colony will simply make more workers.

  If there's been no luck in finding the nest, rinsing the deck with a citrus-based cleaner can help discourage foraging ants. If they cannot smell the trails that their fellow workers have left, they will tend to look elsewhere for food.

Prevention

• Finding ants on the deck isn't uncommon but you can prevent it. Properly seal any food left out on the deck even for an afternoon, whether it's in a plastic bag or on a plate covered with a bowl. Don't leave soda cans or other drinks out, as these can attract ants overnight. Clean up any spills, as well as any food that might fall through the slats of the deck to the ground beneath. Don't leave pet food out; feed only what the animal will eat immediately.

  Check potted plants for insect infestations, as aphids and other pests that produce a sweet, syrupy substance can attract ants. Treat any infected plants immediately. Empty all garbage cans on the deck daily.