24 months old biting and hitting other kids !! What could be the reason of that ?

A. Two reasons are there either your child has learnt it from somewhere in your child finds it funny because a lot of kids do it it’s normal but either their parents teach them the same thing or they learn it from somewhere in the surrounding or television and then not understand the severity they just find it funny so you have to give counselling to the child that you should not be doing it as other kids are also going to hit you