In 2019 I rescued a mauled mated Lasius Niger Queen from the clutches of an established Niger colony. With two damaged legs, looking worse for wear, I placed her in a plant pot I use to grow Sedum (Which by the way is great for a species of Aphids the Nigers love). By Winter I had completely forgotten that I have put her in the pot and as the pot was in the garden left to the elements she left mind my completely.
However, this years, whilst moving some Sedum from the pot I disturbed some tiny Niger workers and Pupae.
Not only had this battered Queen survived but she had successfully created a colony.
Now known as my 'Accidental Nigers' their chances of survival have improved.