My 1.5 year old twins like to bite each other whenever they fight over anything resulting in many bite marks. It might be teething but they have teethers already. How can I stop this behavior?

It is normal that kids bite each other. Ask any childcare center and there will always be cases of biting. They learn to explore the world with their teeth since young so that's their best attack and defense mechanism. We have to educate them firmly this behaviors is wrong. Really have to set a very very firm tone but don't use threat. Teaching siblings to share is sometimes very hard especially when both are the aggressive type . But since they are still so young keep trying to educate them. It is also good to teach them that sometimes it is not about sharing or about the elder have to give in to the younger one. We have to teach them the meaning of "wait", let the other sibling finish playing g with something first then the other one take his turn