DALLAS - In what sounds like a really low-budget horror film, voracious swarming ants that apparently arrived in Texas aboard a cargo ship are invading homes and yards across the Houston area, shorting out electrical boxes and messing up computers.

The hairy, reddish-brown creatures are known as "crazy rasberry ants" -- crazy because they wander erratically instead of marching in regimented lines, and "rasberry" after Tom Rasberry, an exterminator who did early battle against them.

"They're itty-bitty things about the size of fleas, and they're just running everywhere," said Patsy Morphew of Pearland, who is constantly sweeping them off her patio and scooping them out of her pool by the cupful.

The ants -- formally known as "paratrenicha species near pubens" -- have spread to five Houston-area counties since they were first spotted in Texas in 2002.

The newly recognized species is thought to have arrived in a cargo shipment through the port of Houston. Scientists are not sure exactly where the ants came from, but their cousins, commonly called crazy ants, are found in the Southeast and the Caribbean.

"At this point, it would be nearly impossible to eradicate the ant because it is so widely dispersed," said Roger Gold, a Texas A&M University entomologist.

The good news? They eat fire ants, the stinging red terrors of Texas summers.

But the ants also like to suck the sweet juices from plants, feed on such beneficial insects as ladybugs and eat the hatchlings of a small, endangered grouse known as the Attwater prairie chicken.

They also bite humans, though not with a stinger like fire ants.