These pipes, covered with string netting, used to be covered with thorn-bushes to prevent ducks from flying away. On shore one can also find several screens on one side of the pipe.
These screens, mostly build of reed mats are arranged in a half herringbone design. Which makes it possible for the decoyman and the Kooikerhondje to move freely without the notice of the ducks.
Ducks permanently situated in the decoy are called decoyducks. Their task is to lure other ducks to the decoy.