Clothes moth larva
Sorting through some clothes that had been in a box behind the wardrobe, out fell what I thought at first were dead clothes moths.
We looked at several under the microscope and they turned out to consist of little rolls of wool fibres.
Suddenly a head popped out of one of them, followed by a Slinky-like body which retracted as soon as we touched it.
It seemed to have a head the other end as well, but that must have been the tail. It moved by dragging its wool roll along.
All unknown to us, we’d been harbouring Case Bearing Clothes Moths whose larvae had been making little tubes out of our clothes.