POTTSBORO, TEXAS -- Texoma has dealt with its fair share of invasive species -- from zebra mussels to blue green algae -- out at Lake Texoma.

Now, Hagerman Wildlife Refuge is fighting its own battle with another destructive creature -- hogs.

Allison Harris was at the refuge as a helicopter gunner took out 170 pigs from the sky.

It's an unusual job that's becoming more and more necessary in Texas.

"We're getting the hang of it. We've got four hours left and hopefully we can catch some more pigs," helicopter gunner Chad Busse said.

You've heard of hog hunting from the ground, but these two shoot from the sky.

Today's objective: kill hundreds of these invasive species at Hagerman Wildlife Refuge.

"It's been a fairly steady problem for the past probably ten maybe fifteen years," Invasive Species Biologist Saul Petty said.

"Wild hogs are very destructive," Wildlife Refuge Specialist Rick Cantu said.

The hogs here are a type of hybrid and they can grow to about 500 pounds.

They're digging into the ground and destroying these wet lands.

"They can grow to very large populations of which we have very large populations on the refuge," Cantu said.

"But you have to remove 70 percent of the population to maintain in a year's time to maintain what you have already," Petty said.

That's where Kibbe Helicopters comes in.

"There's definitely some issues here. There's a lot of torn up crop land and stuff like that and we're just trying to get it under control," Kibbe Helicopters owner Avery Kibbe said.

The helicopter pilot will sit on the left while the shooter sits beside him with hopes of taking out hundreds of feral hogs.

To be exact, they'll need to shoot 500 to 600 hundred hogs to maintain the hog population.

"Oh, we're probably up around 60 to 70 pigs right now," Busse said.

"What we try and do is work them into the open country like kinda into these farm fields or something real low," Kibbe said.

"This is a 223 AR 15. You have to put a shell deflector on here to keep the brass out of the blades of the chopper or there cold be some major problems," Busse said.

The pilot and his gunner get a map of the refuge, plug it into their GPS and track the hogs from the outside in.

They'll end the day having taken out 170 hogs, but they'll be back at it tomorrow.

"Hopefully double that. We're hoping for probably close to 200," Busse said.