There is this cartoon...

Chickens are gathered together, possibly in a coop or a farmyard.

One chicken says to another, "I'm telling you, They're eating us!" This chicken is warning the others about the real and present danger of being eaten by humans.

Another chicken replies dismissively, "You and your conspiracy theories..."

The humor comes from the irony that the danger is real and obvious, and that the dismissive chicken treats it as a wild theory.

The real joke, however, is realizing that the reader thinks they're only referring to chickens.