Reported by Brad Penner, STATEWIDE Correspondent

The fence that guards the entrance is sturdy chain link topped with three rows of barbed wire. Unauthorized visitors are unwelcome. Only those with a key may pass through the gate. Inside more layers of security await researcher Dennis Berkebile.
[Dennis Berkebile] When we get to work each day, we come through the main entrance and the main entrance has an electronic lock on it and so we need the electronic pass card to get through. When we first enter, we enter a locker room where we take off our street clothes and we place them in a locker.
From there, workers walk through a shower area into another locker room where they dress in clean lab uniforms. Everything from the outside world is left behind. Security cameras and alarms provide another barrier to intruders.
[Steve Skoda, researcher] We pride ourselves in going the extra step with the biological security.
Biological security? Just what are these researchers studying? What's going on in this lab?
[Berkebile] We have 15 different strains of flies that we rear in the laboratory.
But these aren't ordinary house flies. They're screwworm flies. The adults are relatively harmless. It's their babies that are dangerous. These are the babies called screwworms because of the way they burrow into their food. In the lab it's a dried blood mixture. In the wild, the cycle begins when an adult lays eggs on an animal's open wound.
[Berkebile] The eggs hatch into the small larvae, the larvae feed on living flesh. This causes an increase in the size of the wound and more flies are attracted, more eggs are laid, and the process continues. This process can eventually kill an animal.
Screwworms were eradicated from the United States more than 20 years ago. Prior to that, they caused a lot of damage to livestock herds in the southern U.S. Today, eradication efforts are focused on Panama and the Caribbean. That program is based in Mexico.
[Berkebile] And so they produce their own flies continuously and they sterilize the flies then with the gamma radiation to be released. The sterile males mate with the wild females. The wild females then lay sterile eggs.
And eventually the screwworm population dies off. The security in this lab is designed to ensure that the screwworms don't escape.
[Jules Russ, lab technician] I have had dreams about escapes though from the lab, you know, where flies have actually got out.
Lab technician Jules Russ admits she was a little intimidated when she started working here.
[Russ] I didn't know what to expect with the whole biosecurity. I mean, you know, you see movies like "Outbreak" and the biosecurity. That was the only intimidation for me.
Part of Jule's job is to sort the adult flies. Each strain has a distinguishing characteristic like eye color.
[Russ] I make sure there is no mutant eye colors in with these, otherwise it would be considered contaminated. The carbon dioxide is what is keeping them asleep. It's going into the tray so it keeps them asleep so we can work with them and manipulate them so they're not flying around the lab.
Here they look for better ways to raise screwworm flies.
[Berkebile] We're trying to improve methods, make them more efficient, make them more cost effective for the screwworm mass ring production.
They have researched how diet affects female egg production.
[Russ] This is just blood that was collected from the hamburger. It's kind of old and rotten and the flies really like it.
These cups of rancid hamburger will soon be home to screwworm eggs. Females will lay about 5,000 eggs in each cup. Dennis Berkebile is researching ways to freeze and preserve those eggs. It could make fly production more efficient at the rearing station in Mexico where they raise and release 500 million flies per week. They look for ways to produce the blood-based media that serves as food and shelter for the screwworm. When the eradication program began in Jamaica, they had to study the flies' mating habits.
[Skoda] We've got a strain of flies from there and they asked us to check if the flies would mate. You want to make sure when you pick out a completely isolated area like that, that you know the flies you're using in mass production will mate. So we did mating analysis and we had to have the flies here in order to do that.
Skoda has done genetic research into the characteristics of different strains of screwworm flies. A grad student developed a quick field test to determine if an animal is infested with screwworms. All of the work is aimed at getting rid of screwworms.
[Skoda] So whatever way you can really help keep this pest once you have eradicated it, keep it from getting re-established in areas that were eradicated, that's what we're here to work on so it covers genetics, rearing physiology, identification, all kinds of things.
Skoda says this is the only lab in the world devoted to screwworm research. It's funded by the U.S. Department of Agriculture and it was built in 1994.
[Skoda] The facility that we're in right now used to be a kitchen to a cafeteria, and the entire facility was destroyed from within or destructed and then the entire frame area that was left and walls were sealed so any holes were sealed either with concrete, mortar, whatever.
The airtight structure of the lab was built inside those walls. Even the air ducts are secure.
[Berkebile] We have a screen on the vent on the inside here. We have a screen on the outside and then we also have a screen in the middle so that if any fly accidentally gets in there, they've got quite a barrier to get through to get to the outside of the building.
Anything that might contain an undetected living screwworm is put in the freezer. Even the plumbing is screened to trap any strays. And if a fly would happen to wake from his gas-induced coma...
[Berkebile] We have like two or three fly swatters in every room.
Even if a screwworm fly got out, it wouldn't go far, at least not this time of year. The flies are subtropical and wouldn't survive Winter temperatures. Steve Skoda admits the security is tighter than necessary but considering the damage these little babies can do, he'd rather be on the safe side. Reporting for Statewide, I'm Brad Penner.

Captioning by Nebraska Captioning Center, Lincoln, Nebraska .