‘Even pigeons look amazing’: the multicoloured magic of a biofluorescent nature walk

Unlike many animals, humans can't see biofluorescence unaided - but with a UV torch, a night stroll looks very different

It is a murky, dank night in the middle of the countryside, a tawny owl is calling, and I am in raptures, stroking a slug. From the nearby blackness, Jeremy Buxton, a farmer, exclaims: Oooh, an earthworm!. Oh, wow."

The brown slug is emitting brilliant fluorescent yellow slime as I touch it; the earthworm is revealing twin tracks of turquoise on its belly. What might appear some kind of experiment with psychedelic mushrooms is actually a new way of seeing the world at night: shining ultraviolet torches to reveal the natural biofluorescence of animals, plants and fungi.