A small amount of the rat poison has been eaten. The tray it is in has not moved. This means rats didn't eat it - they eat everything and chew or move the plastic trays.
I'm not bothered by mice, they are always present and do little damage in small numbers. I left the remaining poison and I'll check again tomorrow.
It was very frosty, sunny, with a clear sky and lovely crisp air. Always a nice place to be.