Egrets and herons, on their middle toes, have a special edge that acts like a comb. They use this pectinate edge to reach up into the special soft feathers on their chest and gather up some of the extra fine fluff that lingers there. Placing the fluff in their beaks it becomes a wash cloth to help clean all the fishy leftovers from their feathers. Here you can see some of that fluff at the end of the beak of this great egret.