A mild day, the ground waterlogged with the past rains, and the grass peppered of earthworm casts, Lumbricus terrestris. A pair of Herring Gulls hunt for worms on the wet soil, rapidly patting it with their feet. The rapid rhythmic pattering creates vibrations on the soil similar to rain, and the earthworms move to the surface. I took a poor quality video, although it shows the behaviour of one of them, looking very intently to the ground and pecking occasionally. During some seconds it uses only one of its legs while keeping balance with the other.