Pest guide

Ants in Texas: fire ants and ants in the house

Most ant problems in Texas homes and yards are fixable on your own. The trick is to go after the colony, not just the ants you can see.

Fire ants #

Red imported fire ants are an invasive species and one of the costliest pests in Texas. Texas A&M AgriLife Extension puts their yearly cost to the state at about $1.2 billion. They build dirt mounds in open areas like lawns and gardens. Step on a mound and the ants pour out and sting fast.

The two-step method #

For yards with lots of mounds (about five or more per quarter acre), Texas A&M AgriLife Extension recommends two steps.

Step 1: Spread bait over the whole yard. Fire ant bait is food mixed with a slow-acting insecticide. Worker ants carry it home and share it with the colony, including the queen.

• When: Late August to mid-October is the preferred window. Bait can work any time it's warm and ants are out looking for food.
• Fresh bait: Use bait from a new, unopened container if you can. Old bait loses its pull.
• Dry weather: Spread it when grass and ground are dry and no rain is expected for 24 to 48 hours.
• Ants active: Late afternoon or evening is often best. Quick test: put a little bait beside a mound. If ants find it within 30 minutes, it's a good time.
• How: Use a hand-held spreader at the rate on the label. Don't mix bait with fertilizer or seed.
• Patience: Baits can take weeks to months to do their job.

Step 2: Treat problem mounds. For mounds next to the swing set, the front walk, or other busy spots, use a mound product labeled for fire ants. The label tells you how much to use and whether to water it in. Keep kids and pets off treated areas for as long as the label says.

Plan to bait once or twice a year. Read Using pesticides with care before you start.

What about boiling water? #

A&M says 2 to 3 gallons of boiling water poured on a mound kills the colony only about 60 percent of the time. Survivors often just move. Boiling water also kills grass and plants, and it's an easy way to get burned.

Hot, dry summers #

In a drought, mounds may seem to disappear. The colony has moved deeper into the soil. Fire ants may also come indoors looking for water. Fixing leaky faucets, AC drips, and irrigation leaks helps. Expect mounds to pop back up after it rains.

Ants inside the house #

Indoor ants are looking for food, water, or a place to nest. Before you grab a spray, know this: spraying an ant trail kills only the workers you can see. A&M warns it can even make things worse by causing a colony to split into more colonies.

Step by step #

Ant colonies move when disturbed, and some kinds have more than one nest. If the nest is inside a wall or under the slab, reaching it may mean drilling. That's a job for a licensed company.

Carpenter ants #

Texas has 14 species of carpenter ants. They're large ants that often nest in damp or rotting wood. In Texas they rarely cause major damage to buildings, according to A&M, so a few workers may not call for an expensive treatment plan. Ant baits sold for kitchen ants usually don't work on carpenter ants. Baits made for carpenter ants do better.

Tawny crazy ants #

Tawny crazy ants (also called Rasberry crazy ants) were first found near Houston in 2002. They show up in huge numbers, nest mostly outdoors, and ignore most baits. Treating inside the house won't fix the problem. This is a good time to call a licensed company.

Winged ants or termites? #

In spring, swarms of winged insects can be ants or termites. Here's how to tell them apart:

Winged ants swarming around a porch light outdoors usually aren't a worry. Winged ants or termites coming out inside the house suggest a colony inside. If you think it's termites, read the termite guide.

When to call a licensed company #

• Ants keep coming back after a month of steady baiting.
• The colony is inside a wall or under a slab.
• You have tawny crazy ants, or carpenter ants nesting indoors.
• Someone in your home is allergic to fire ant stings and the yard is full of mounds.

Before you hire anyone, check the license and make sure it covers the right category for the job. If you'd rather try more on your own first, see Do it yourself or hire a pro.

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