Moth larvae ID? Or some sort of slug?

Moth larvae ID? Or some sort of slug?

Observation - Moth larvae ID? Or some sort of slug?. Description: Seen on the Black Isle in Scotland. Leaves an orange dusting/stain afterwards. Quite a few of them around, different sizes: 2/3cm and 3/4cm. They were seen amongst green leafed plants and some nettles, not far from the coast/loch.

Seen on the Black Isle in Scotland. Leaves an orange dusting/stain afterwards.

Quite a few of them around, different sizes: 2/3cm and 3/4cm.

They were seen amongst green leafed plants and some nettles, not far from the coast/loch.