You are quoting the opening of a traditional English nursery rhyme. The full rhyme answers the question in a playful way.
Full rhyme text
Pussy cat, pussy cat, where have you been?
I've been to London to visit the Queen.
Pussy cat, pussy cat, what did you there?
I frightened a little mouse under her chair.
Origin and meaning
This rhyme is an old English nursery rhyme, commonly taught to young children in English-speaking countries.
Many accounts link it to Tudor-era England and Queen Elizabeth I, telling a light story of a cat visiting the Queen and chasing a mouse near her throne.
