What’s this?

I think a lot of Scotland has flat worms. We had a population on one plot at my other site. Easily brought in on the bottom of pots etc.

Horrible things, an abomination in nature.

After the research yesterday we have approximately 21 species only 4 are actually native flat worm.

Sc I have just came across this thread, I was bothered with the flatworms, don't know whither continually checking and disposal of them has cleared them, but I have found that since I started using seaweed in the garden I don't come across them now, and I have found a good number of earth worms in the soil I have been shifting you could also try changing the soil pH to acidic which might help