In this scene, the 2nd most intelligent species on Planet Earth, dolphins, sing a little ditty to the 3rd most intelligent, mankind, before they leave the planet forever. This is the opening scene of the "The Hitchhiker's Guide to the Galaxy(2005)", a zany comedy based on Douglas Adams' even zanier books. Here are the lyrics:

So long, and thanks for all the fish
So sad that it should come to this
We tried to warn you all, but, oh, dear

You may not share out intellect
Which might explain your disrespect
For all the natural wonders that grow around you

So long, so long, and thanks for all the fish!

The world's about to be destroyed
There's no point getting all annoyed
Lie back and let the planet dissolve around you

Despite those nets of tuna fleets
We thought that most of you were sweet
Especially tiny tots and your pregnant women

So long, so long, so long, so long, so long! So long, so long, so long, so long, so long! So long, so long, and thanks for all the fish!

If I had just one last wish
I would like a tasty fish!
If we could just change one thing
We would all have learnt to sing!

Come one and all
Man and mammal
Side by side
In life's great gene pool!

So long, so long, so long, so long, so long
So long, so long, so long, so long, so long, so long

and thanks for all the fish!