Toddler Biting

Ashwin's behavior is causing us fresh headaches.
The playschool authorities informed us yesterday that Ash bit a fellow playmate for grabbing the toy he was playing with. Apparently he has been doing it all these months in playschool but until now there had been no major casualties. But this time round he managed to get his teeth well into the poor kid's fair arm that it left tell-tale signs. The kid's parents rushed him to the dr for a tetanus injection, and blasted the school authorities for the poor care. Hence Ash was kept in isolation yesterday during playhours!
But websites on children tell me that it is not abnormal behaviour and is a part of the toddler years:
Biting from frustration
Frustration happens when children get into situations that they can’t handle. Children under about three or so are not usually ready to play in a cooperative way with other children in groups. If they are in a group and another child takes their toy they may respond by hitting or biting. They have not yet learned other ways to cope.
If biting gets a strong response, which is likely, they will see that it is successful and may try it again.
Self-Assertion. The accident report given the parent by an educarer at the end of the day reads, "Child was bitten during a struggle over a toy." Toddlers have very limited language skills. Consequently, biting is a way to register a complaint.