The ruddy turnstone's short, slightly upturned bill is a lever rather than a probe. The bird pushes under stones, shells, weed and driftwood and flips them over, then takes the amphipods, insects, molluscs and worms exposed beneath. Birds often work in loose groups, and larger objects are sometimes shifted by more than one bird.
The diet is unusually catholic for a wader. Alongside invertebrates, turnstones have been recorded taking carrion, fish scraps, discarded human food, and the eggs of other birds, including in tern and gull colonies. That breadth is part of why the species winters successfully on coastlines around the world rather than depending on a narrow prey base.
Breeding plumage is a strong tortoiseshell of black, chestnut and white that looks conspicuous in the hand and disappears entirely against Arctic lichen and rock. The distinction worth keeping is between diet breadth and habitat breadth: turnstones eat almost anything, but they need shoreline with cover to turn, and are scarce on clean unbroken sand.