I think slug is a kind worm so I won't be kills it. I just take it from my bathroom and allow it to go anywhere. Then I will clean my bathroom once again and make sure that there should not have other slug or any other worms.
Cover up any holes in your bathroom walls and window screens. Leave out a shallow dish filled with warm ale on your bathroom floor. (Slugs like beer, so any others hiding there will crawl into the dish and drown. ) Just don't panic. It was probably a one-time thing.
My hunch is that this is a one-time thing. Slugs do not normally live in bathrooms. It's possible you might have brought it in on your clothing, your shoe or, if you had been swimming, on a wet towel. Don't be too stressed about it.
You could try putting salt onto the floor. They can get in through cracks or even if one got stuck to someone. Sprinkle salt in the doorways for a little wile, they should stop coming.
The same thing happened to me and I thought "ew ok one time thing" today I found another one! Found out that I probably have a leak in the plumbing. I am going2call a plumber,for now I am putting a trail of salt.
