A flood of voracious ants is heading straight for Houston, taking out computers, radios and even vehicles in their path.

Even the Johnson Space Center has called in extermination experts to keep the pests out of their sensitive and critical systems.

The ants have been causing all kinds of trouble in five Texas counties in and around the Gulf Coast. Because of their sheer numbers, the ants are short circuiting computers in homes and offices, and knocking systems offline in major businesses. When IT personnel pry the affected computers open, they find the machines loaded with thousands of ant bodies.

"These ants are raising havoc," said Roger Gold, professor of entomology at Texas A&M University in College Station. "They're foraging for food and they'll go into any space looking for it. In the process, they make their way into sensitive equipment."

The ants have been dubbed Crazy Raspberry ants after Tom Rasberry, owner of Budget Pest Control in Pearland, Texas. He first tackled this particular type of ant back in 2002. Since then, the problem has only escalated.

Rasberry told Techworld's sister publication, Computerworld, that the ants have caused a lot of trouble for one Texas chemical company in particular. Not wanting to name the company, he said the ants shorted out three different computers that were running a pipeline that brought chemicals into the plant. The ants took down two computers last year and one in 2006, affecting flow in the pipeline each time.

"I think they go into everything and they don't follow any kind of structured line," said Rasberry. "If you open a computer, you would find a cluster of ants on the motherboard and all over. You'd get 3,000 or 4,000 ants inside and they create arcs. They'll wipe out any computer."

The Johnson Space Center called in Rasberry a month or two ago in an attempt to keep the ants out of their facilities. Too late. Rasberry said he's found three colonies at the NASA site, but all have been small enough to control.

'With the computer systems they have in there, it could devastate the facility," said Rasberry. "If these ants got into the facility in the numbers they have in other locations, well, it would be awful. I've been in this business for 32 years and this is unlike anything I've ever seen. Anything. When you bring in entomologists from all over the United States and they're in shock and awe, that shows you what it's like."

The Johnson Space Center referred all questions about the ants to Rasberry.

The ants, which are tiny and reddish, aren't native to Texas. Officials believe they came off a ship from the Caribbean, said Paul Nester, a programme specialist with the Texas AgriLife Extension Service. They were first spotted about six years ago.

Gold said in the last few years they've spread in a radius of about 50 miles. And now they're moving into Houston, the fourth-largest city in the country.

"Fifty miles might not seem like a lot until you realise they're moving into Houston," said Gold. "It could really affect a lot of people's lives."

A big problem here, noted Nester, is how quickly their numbers are multiplying.

A queen fire ant, long a problem in Texas, can lay as many as 1,000 eggs a day, he said. The Crazy Raspberry ants are thought to be as prolific. However, an ant mound normally has one queen. The new ants have many queens so they're able to multiply their ranks that much more quickly. They also don't go to the trouble of building ant hills. They simply nest under anything they can find - a log, a tire or a pet's water bowl - and then they quickly move on as they spread further into the state.

Nester said the ants swarmed into trucks at a shipping company, shorting out the radios and even the vehicles themselves.

Gold said the ants got into an engine compartment at a sewage treatment plant and shorted out the pumps so they couldn't move the sewage out. He added that they've also overrun a subdivision and caused a lot of electrical damage to houses there.

Part of the problem is that exterminators have found it nearly impossible to kill the ants. Oh, you can kill some of them - the first wave, maybe. However, there are so many more ants coming behind them, that the first wave falls dead in the insecticide and the subsequent waves merely walk on the dead bodies, keeping themselves out of the poison and safe from harm.

Gold warned people not to spray pesticide inside their computers and to simply call in the professionals to prevent mixing up poisonous concoctions or storing the potentially harmful partly used insecticides.