WE REALLY have no business comlaining when those tiny black creatures, armed with extended swords for ears, attack our picnic spreads each summer. After all we are invading their territory.

However, when we're happily dining in the privacy of our own castles and spot a miniature troop marching single file toward our food supplies, invading our territory, well then, it's time to fight back.

In the event of any such confrontations, it's important to know some basic self-defense tactics:

Ants can appear throughout the year but are more active during the summer months. They usually enter a house in search of food scraps. House ants build their nests around house foundations, sidewalk cracks, in the ground or in tree stumps. Although they may build nests close to house foundations, they don't create any serious damage.

Workers are the form of ant most commonly seen in the home and on sidewalks. They are black in color, wingless and about one-eighth inch long.

The homeowner should be aware that there are about 20 different kinds of insecticides. Although the brand names vary, most of the products on the makret are equally safe and effective. However, there are certain chemicals that, because of their effectiveness, should be contained in all spray pesticides. The names to look for on the label are; pyrethrin, diazinon, baygon, resmethrin and dichlorovos.

Jay Ellenberger, a pesticide product specialist at the Environmental Protection Agency (EPA), claims that all of the above chemicals are successful in combating ants, but each works a little differently. Take, for instance, pyrethrin. Pyrethrin degrades in about a day, so the homeowner would need to spray more of it more often until the ant problem ceased. Diazinon and baygon, on the other hand, last longer -- about 10 days -- therefore less frequent doses would suffice.

There is a cosmetic advantage to using pyrethrin. Pyrethrin knocks the insect out immediately so it can no longer pursue you or your food supply. The pyrethrin takes a while to actually kill the bug, but in the meantime the homeowner can dispose of the invading critter without having to chase it all over kingdom come. Stewart Bunn, a Fairfax County Extension agent, points out that pyrethrin is more often used to fight off insects that can "attack you," such as wasps and bees. To get rid of ants, he recommends an aerosol containing diazinon.

Most of the pesticides work by being absorbed through the ant's body. The pesticides behave like an intoxicant that, depending on the spray's chemical formulation, affects the ant physiologically via its nervous system or its muscles. Spraying the homeowner's kitchen or any other room with a pesticide is safe. Be sure to cover pots and dishes and put away food before you spray. The fumes will not kill you. "However," suggests EPA's Ellenberger, "avoid as much inhaling of the fumes as possible. Leave the room after you spray and be sure to open the windows wide for about an hour."

"Many times homeowners are not treating the source of their ant problem," says Ellenberger. "They spray the trail of ants that they see creeping toward their kitchen cupboard and maybe those ants are killed. But it is necessary to find the source of the ant colony -- the ants' nest -- in order to completely rid yourself of any ant problems. You have to discover where the ants are entering from the outside and then treat that area with an insecticide."

"And," he adds, "because it might be difficult for the average joe to find the ants' nest, or if the ant problem persists, it is sometimes necessary to contact an exterminator."

In the home the places to be sure to spray are windowsils, door frames and the baseboards of the house. Outside, spray the foundations of the house and any anthills you find close to the house itself.

In addition to the food-seeking ant, there is another type, the carpenter ant. "Carpenter ants," says Bunn, "are often confused with termites. However, they are as easily disposed of as regular ants and don't usually require an exterminator as termites do."

Carpenter ants are between 1/4 and 3/4 inches long and are black, or black and red. They have the 90-degree-angled antennae particular to all ants, while termites have curved antennae. The ants also have a large upper wing; termites have a pair of wings that are about the same size. Carpenter ants are found in the house, but unlike regular ants they are not necessarily after food. Instead they're searching for soft, damp wood that can be used as a nest. Unlike termites, carpenter ants do not eat wood. Their ant colonies are usually localized in one area. They don't spread throughout the house, as do termite colonies. To rid an area of this type of ant, Bunn suggests, spray the nest with diazinon."And, if what you have is termites, don't panic. It takes a long time for termites to destroy your house. Call an exterminator or your local county extension office for assistance."

At the onslaught of the ant season, says Bunn, use common sense:

Clean up all spills and food particles after cooking.

Keep all parts of the house clean -- including the outside. Clean up after barbecuing outdoors. Greasy grills can and do attract ants.

Don't leave food open on the counter.

Inspect outside doors and windowsills regularly for cracks or openings that would allow ants to come in.