Most Texans know something about fire ants, especially those of us who have been stung, and about the small sugar-eating ants that invade pantries.

But what about Texas leaf-cutter ants, velvet ants and carpenter ants? How much do you know about these pests and how to protect yourself and your property?

Leaf cutter ants (Atta texanus) can be a serious problem for gardeners. They live in large underground colonies that may contain as many as 2 million ants.

Texas leaf cutters remove the leaves from a variety of vegetable, fruit and ornamental plants, but they don't eat the leaves or use them to line a nest; these ants are gardeners. On the leaves they harvest and take into their nests, they grow a particular type of fungus that is their only food.

These ants are rust to brown in color and vary widely in size. Worker ants range from 1/16 to ½ inch long, while the queen is about ¾ inch long. Curiously, all the workers are wingless females. Mating flights occur during the spring.

A large colony of leaf cutter ants can defoliate a small tree or shrub in a matter of hours. And they are hard to get rid of. Plants can be dusted with Sevin, Orthene or permethrin, but these products don't affect the ants that are underground.

The only pesticide specifically labeled for leaf cutter ants is Grant's Total Ant Killer Bait. But according to Texas Forest Service tests, this bait is just 30 percent effective with one application, so follow-up applications will be needed.

Other control measures include blowing or sprinkling contact insecticide dusts such as Orthene or Sevin into each entry and exit hole in the mounds. Be extremely careful when applying these insecticides and wear a mask to avoid breathing the dust.

Velvet ants are not really ants; they belong to the wasp family Mutillidae. They are commonly referred to as velvet ants because the females are wingless, look and behave like ants, and are covered with a velvety "fur" composed of red and black hairs. The males look and act more like wasps.

The red velvet ant is actually a wasp, and the female can deliver a powerful sting.

In addition to being misnamed, velvet ants differ from ants in other ways. Females inflict painful stings, which should be cleaned and sterilized. If a sting causes a rash or breathing difficulty, the victim should see a doctor promptly.

It is almost impossible to eliminate these insects. Teach children to avoid them, and wear shoes when in an infested area. Fortunately, velvet ants usually travel alone.

Carpenter ants are larger than most other types of ants, and because of their nesting habits, they can damage homes and other buildings. Instead of eating wood as termites do, they may hollow it out to make nests.

While termites feed indoors and live outdoors, carpenter ants feed outdoors and can make their colonies indoors. According to Michael Merchant, an urban entomologist with the Texas Cooperative Extension Program in Dallas, Texas carpenter ants usually nest in trees and normally are not destructive to homes.

Dr. Merchant, who has written extensively about ants, says Texas carpenter ants "prefer to nest in existing voids and cavities and do not usually excavate large nests in wood."

"They are not as destructive as species found in the northwestern and northeastern regions of the United States," he writes. If uncontrolled over a period of time, however, they can do a considerable amount of damage.

Carpenter ant bait products are available for do-it-yourselfers, but because you may need to drill into areas around pipes, I recommend hiring a professional exterminator. Make sure he or she is licensed and insured.

H.S. Stevens is a lifelong gardener and former vegetable specialist with Texas Cooperative Extension.

E-mail houseandgarden@dallasnews.com