Describing his first road trip with Lolita across the USA, Humbert Humbert (the narrator and main character in VN's novel Lolita, 1955) mentions a fly that would settle and walk in the vicinity of Lolita's navel or explore her tender pale areolas:
A fly would settle and walk in the vicinity of her navel or explore her tender pale areolas. She tried to catch it in her fist (Charlotte’s method) and then would turn to the column 'Let’s Explore Your Mind.'