our dts have been biting each other, and occasionally ds1. they are 19mo and it is mostly when one is frustrated, eg the other has a toy they want. so far, the biter is told off and made to face the wall while the bitee is made a fuss of for a few seconds. then the biter is asked to say sorry and give the biter a cuddle. this all happens without protest, but does nothing to solve the problem which has been ongoing for a week and getting worse. any suggestions?