Fred Cory, Gladesville, NSW

I nd these little slugs after rain, usually on a fatal mission to cross concrete where they dry out. ey range up to about 80mm long by 3mm, with two versions – one is purple, with a thin white stripe, and the other is brown, with a wider stripe. eir slime is very sticky. Can you identify them?

Martyn Robinson says

These ‘slugs’ are actually land planarian worms – one of the world’s best regenerators and fierce predators. They feed on a variety of small animals and can regenerate a whole new individual from just a small piece of themselves. They have a combined mouth and anus, as their gut is a simple sack, so everything that goes in must leave by the same opening.