Most of the cockatoos I have worked with snap their mandibles together when they are excited or stimulated. Since the beak is actually very sensitive, snapping or grinding the mandibles together can be very pleasurable. If I was to compare it to a dog behavior, I think it is similar to the way some dogs scrunch up their faces and lick the air when they are enjoying a good scratch. Cockatoos are not the best talker of the parrot species. The best talker is considered to be the African Grey Parrot, but the Cockatoo makes up for this by far because of their loving kind nature.
Cockatoos mate for life.
Cockatoos can die from a broken heart if removed from someone they love, even a human companion or mate. Cockatoos often choose a human being as a mate and they are known to observe normal mating habits with this human being. Cockatoos often love sleeping with human companions. This is one of the ten major causes of death in the Cockatoo species as a whole. Cockatoos can sometimes be heard screaming over a block away from their home.