[c-smile]

We MUST, having life on just one planet waiting for the next mass extinction event here is too optimistic.

[AlbertCory]

Why must we? There are other intelligent life forms in the Universe, undoubtedly. What makes us so special?

[vsuperpower2021]

They are also 20 feet tall and wear propeller hats, no doubt.

[exe34]

We're the only ones we've found so far.

personally I'd say don't bother, but I'm a nihilist.

[AlbertCory]

"don't bother" doing what? Looking for them?

The chance of our ever encountering one in person is close to zero. We might find evidence that they're there, but that's about it.