Small crows

There was a bonsai tree in Japan. A cockroach climbed the trunk and sat on one of the branches looking as black as a crow.

Then it climbed back down again, went outside, and got into the branches of a fully-sized tree, saying, "I have looked like a crow in one tree, why not another?" The cockroach's charisma was so persuasive that the universe adjusted itself to suit its beliefs, and it grew to the size of a crow.

Flying around, it tormented the real crows, who, to escape its teasing, shrank to the size of cockroaches and made nests in bonsai trees.