This is a first that isn’t a cause for celebration: my first flatworm.
Last year, I thought I found some flatworm egg cases, but I didn’t see any actual worms. Today, when I was moving a pile of bricks in the yard, I found what is definitely a flatworm. I think, from looking at photographs on the internet, that it is an Australian one (Australoplana sanguinea).
These flatworms are bad because they eat earthworms. Fera (the Food and Environment Research Agency) has factsheets available to download on the Australian* and the New Zealand flatworm*, as well as a “Flatworm code” for nurseries.
*nb – because of the settings with the Fera website, these link directly to the pdfs of the factsheets via google, alternatively you can go to the GB Non Native Species Secretariat site and search from there.