Wayward knights

I have noticed that my chess pieces appear to be multiplying. Each time I open my pieces box there is one more pawn.

I suspect the White Queen is seeing one of the knights on the sly. The extra pawns are brown so a black knight must be the key suspect, but how do I find out which one. I have set up a CCTV system in the communal living room where I keep my pieces but after watching through literally 7,206 hours of footage I have seen nothing untoward happening in the box.

What is the best form of contraception for tumescent knights? If I don't do something soon there will be a surfeit of unwanted pawns. I mean who wants brown ones which side would they even play on?

You've lost your form big dog. Dig deeper.

I had to dig deep into the chess literature to find an answer to this one. It seems the preferred method is to play more prophylactic moves.