California greeted the arrival of its newest visitors from foreign shores by breaking out the Spam and initiating a massive hunt for them.

State agriculture officials responded to an invasion of aggressive big-headed ants from Africa—in the Orange County city of Costa Mesa—by beginning placement of 1,500 traps, loaded with the popular meat derivative as a lure. This is the first appearance of Pheidole megacephala in the state and they seem to be making themselves at home. 

The ants aren't considered a threat to humans, unless one considers finding them storming your house or inundating your swimming pool a threat. But they could spell trouble for native ants, agriculture and ecological balance.

The ants were first identified last month by amateur entomologist Gordon Snelling of Apple Valley, who noticed them while visiting in Costa Mesa, according to the Orange County Register. He alerted officials and the race was on to discover how far they may have strayed from that home.

The answer was: a ways. 

A team of UC Riverside scientists and state and local agricultural officials quickly found 31 ants in other locations and that was enough to trigger a countywide response. Twenty traps will be placed in each of the county's 79 square miles while officials wait with bated breath to learn the results.

While Pheidole megacephala is a nasty pest, it is not the worst ant to make a public appearance in the past month. They are not even the worst big-headed ant.

That honor would go to Cephalotes ants that roam from the South to South America. Wired profiled the “world's most badass ants,” who use their heads as doors to bar intruders from their colonies. They also go airborne to dodge predators and glide on air currents until they skydive to their landing place.

California doesn't have those ants. But the Global Invasive Species Database does call Costa Mesa's big-headed ants “one of the world's worst invasive ant species.” It is a “serious threat to biodiversity” and “is known to chew on irrigation and telephone cabling as well as electrical wires.” They are omnivorous. 

Pheidole megacephala “has been nominated as among 100 of the 'World's Worst' invaders.”

–Ken Broder

To Learn More:

Massive Ant Hunt Gets Underway Monday with Special Bait: Spam (by Scott Martindale, Orange County Register)

Absurd Creature of the Week: World’s Most Badass Ant Skydives, Uses Own Head as a Shield (by Matt Simon, Wired)

"Bigheaded" Ant Colony Discovered in O.C.; Officials Investigate (by Bradley Zint, Los Angeles Times)

Bigheaded Ants Invade Costa Mesa (by Matt Coker, OC Weekly)