Little Grebes are very good parents.Tiny newly hatched chicks are given lifts on the back of the parents. They also provide a constant source of food to help them grow fast. I have also watched the adults teaching the young how to dive and catch their own fish and insect larva.
However there is a time when the youngster has to stop begging the adult for food and go off to explore the world by himself.
This appears to be just that time. The juvenile had been calling for food, when the adult suddenly shot over and basically attacked the youngster. That was not a playful little nip. It was a good proper bite. The young one swam off but soon came back, this time he got caught by the neck and forced underwater. By the time he surfaced I think he was beginning to get the message that the easy life was over and it was time to go.