The trees were sentient. They had always been sentient of course, but the world has grown too horrifying for them to ignore.
"Bob said the world is ending"
"You won't make it till Christmas"
Some of the trees felt that nothing mattered anymore, and teased each other lovingly.
"Is it ready?"
The so called ducks had morphed into humanoid villains intent on destroying the sentient trees with a megabomb. (dramatic pause) And the trees knew it.
The trees devised a plan to eliminate the ducks entirely: Operation Lemonade. But the lemonade stand was just a cover-up, a distraction from their real plan.
Instead, the trees fell in the forest when no one was there to hear it. It didn't make a sound, but it did collapse the ducks' secret laboratory.
However, the pressure from the collapse caused the bomb to explode and the sentient trees were no more.