The Dream Book of Self-Knowledge
- flying out of a hole: thoughts of sex
- flying into a person's mouth: this person will try to attract others with talk of sex.
- hanging up fly-paper: an attempt to break away from instinctual and sexual thoughts.
- seeing flies stuck to fly-paper: confirmed victory over fickle thoughts of an instinctual and mainly sexual nature.
- killing: the attempt to break away from instinctual and sexual thoughts, though this act only has a temporary effect.
- seeing dead flies (without the dreamer's involvement): confirmed victory over fickle thoughts of an instinctual and mainly sexual nature.
