Jensen: General, I'll make a deal with you. You make me a sergeant in charge of the booze and I'll enlist. Make me a sergeant in charge of the booze! Make me a sergeant in charge of the booze.
Robert Graham: And I thought today was the end of them.
Dr. Harold Medford: No. We haven't seen the end of them. We've only had a close view of the beginning of what may be the end of us.
Dr. Patricia 'Pat' Medford: Now destroy everything in here. Burn it.
Robert Graham: What?
Dr. Patricia 'Pat' Medford: I said "Burn it!" Burn everything.
Dr. Harold Medford: We may be witnesses to a Biblical prophecy come true - 'And there shall be destruction and darkness come upon creation, and the beasts shall reign over the earth.'.
Dr. Harold Medford: Get the antennae! Get the antennae.
Answer: Like the General said, the less people that know about the ants the better. They were a special task force assigned with the equipment and deputized to use any and all measures to stop the ants. Since the movies was set in the 1950's, James Arness and James Whitmores were most likely veterans of WW II and Korea.