To Disappear

So, a few days ago on TV, I saw the end of a documentary about what would happen if every human on Earth suddenly disappeared.
Now, in movies, you get characters who want to get rid of humans because they're destroying the planet. The character that comes to mind is Fujimoto-Ponyo's dad. He wants all humans to disappear because they're polluting the oceans. And the first time I saw Ponyo, I couldn't bring myself to think badly of him when he said that. I can completely understand why someone would want to get rid of humans, though some humans are fighting tooth and claw to protect the planet.
But as I was watching that documentary, I started thinking how lonely the planet would seem without humans. All the other animals would thrive, and according to the documentary, most of humans' mess would be cleaned up in about a hundred years. Global warming, nuclear waste, ex (That's only if all humans completely vanish now. That doesn't count if we keep pumping more toxins into the air).
But one thing they didn't address (unless it was in the beginning of the show that I didn't see-but I doubt that) was invasive species. Humans have introduced all of these non-native species into their non-natural habitats and some of them are completely taking over and destroying the native species and the habitats. There's cane toads, zebra mussels, and hundreds of plants, bugs, and other animals. What would happen with them if all humans vanished? Would they take over the planet, or would they eat themselves out of house and home? Or would something else take care of them?
Sigh.