Originally Posted by Ryllharu
The whole sequence is a variation on a quote from an old Simpson's episode. Bart raises two eggs from a nest where he killed the mother bird, and predatory lizards hatch from the eggs instead. They start to eat all the pigeons in Springfield, and the following exchange occurs:
Skinner: Well, I was wrong; the lizards are a godsend.
Lisa: But isn't that a bit short-sighted? What happens when we're overrun by lizards?
Skinner: No problem. We simply release wave after wave of Chinese needle snakes. They'll wipe out the lizards.
Lisa: But aren't the snakes even worse?
Skinner: Yes, but we're prepared for that. We've lined up a fabulous type of gorilla that thrives on snake meat.
Lisa: But then we're stuck with gorillas!
Skinner: No, that's the beautiful part. When wintertime rolls around, the gorillas simply freeze to death.