Killing the queen doesn't stop the Tunnelers, though. If you talk to Ulysses about them he mentions it's not really a matter of "if" they're going to mess with the rest of the wasteland, but "when." It's impossible to kill them all, at worst the Courier cripples their invasion, but they'll persevere.

They will repopulate.

And they'll spread.

They'll have numbers, and complex underground routes, and strength, and they'll come in full force when they do.

New Vegas will fall-- New Reno will fall-- The Enclave and the Brotherhood, wiped out-- The Bull and the Bear will be subject to the Tunnelers. NO ONE, will be prepared-- they could appear anywhere in the desert RIGHT NOW and sack a city before anyone knew anything. They spread like wildfire and they can tunnel up through anything at anytime and ruin everything. They are the single largest threat to America, and no one even knows it. They've already won the west, they're just waiting to launch the slaughter.

And then, when the west falls, they'll go east.

gg, humanity