howl at the moon

After the stereotypical behaviour of wolves howling at the moon in folklore.

howl at the moon (third-person singular simple present howls at the moon, present participle howling at the moon, simple past and past participle howled at the moon)

1. (idiomatic) To spend considerable time and effort fruitlessly in a hopeless endeavor.

• “howl at the moon”, in Collins English Dictionary.