My son recieved four ducks for his birthday...two mallards and two pekins. One of the pekins is very clumsy (hints the name). When we let them out of there cage this morning clutz started limping and falling over. He can run IF he feels he is in danger but not for very long. He can also still swim just fine. i should add that he is eating and drinking like normal too. I am worried and not sure what to do about the limping.