It happens around Mother's Day every year. Formosan subterranean termites take flight from their colonies and swarm across large areas looking for a mate. For homeowners the sight of thousands of termites landing in their yards sets off a panic.
Alan Frumkin is a homeowner on the southeast side of Houston. He says he had a bug zapper on in the backyard when the swarm hit last week.
"I didn't turn it off, and sometime during the evening hours, termites piled on all around the lamp, five or six layers deep of electrocuted termites. Thousands."
The Formosan subterranean termites have predictable mating habits. They take flight on nights when there is little wind usually following a few days of rain. They swarm around outdoor lights looking for a mate. Once they find a mate they go underground to start reproducing.
Dr. Robert Puckett is an entomologist with Texas A&M. He says the mating window for the Formosan's is narrow and easy to remember. It happens the week before and the week after Mother's Day.
"All that really relates to is that during this time of the year ecological cues and characteristics in their environment sort of sync up and indicate to them it is time to swarm. The swarms are nothing more than a mating opportunity for new generations of termites," said Puckett.
His office has been receiving reports of the swarms for the past week.
"We've gotten reports already from pest management professions from Beaumont over to where you guys are (Houston) then down to the tip of the Rio Grande Valley."
The Formosan termites are an invasive species. They originated in southern China. They came to the United States through infected wooden crates in New Orleans and Lake Charles sometime after World War II. From there they've spread along the southeastern parts of the country. This breed of termite has been reported in 11 states.
The Formosan subterranean termites have never been eradicated from an area once an infestation begins. While they live underground as their name indicates they can also establish colonies inside trees. A mature queen is a prolific breeder laying as many as 3,000 eggs a day. The climate limits their spread as the eggs can't hatch in temperatures below 68 degrees Fahrenheit (60 C).
The termite swarms can be quite large. The swarms are so thick that they have forced the postponement of baseball games in New Orleans. One termite swarm was so large that it showed up on the radar of the National Weather Service in 2016.
Tracy Baird is a homeowner in Seabrook who noticed a few termites that made their way into the bathroom last Tuesday. She armed herself with bug spray when she began to realize the size of the swarm.
"By the time I found the spray and came back upstairs they were crawling everywhere. It was creepy and disturbing. I was spraying all around in and outside the doors and windows," said Baird. She said a friend reminded her to turn off all the lights. After about 30 minutes the swarm stopped, and she could start sweeping up the dead bugs.
Dr. Puckett says the swarmers are poor flyers and probably only traveled a short distance. He says the swarmers don't necessarily mean a home is infected but it does mean the home is near a developing colony of termites.
"If you see them within 5 or 10 feet of your house – if that pairing is successful and mating goes well, and she is capable the queen is capable of laying her first round of eggs. Then you have a colony, a brand-new colony that is growing right near your house," said Puckett.
Dr. Puckett says he advises people to hire a professional to do a home inspection and possibly treatment if their home was in the vicinity of a termite swarm.