Your question is too short. It would take a whole book to respond to the many possible reasons and variations...
Read the book, Raising Our Children, Raising Ourselves.
And, consider homeschooling. Some kids are not made for school.
children need to be taught the importance of respecting others property. this child that you are refering to takes others for granted and therefore does not mind hiting others and snatching things from others(as mentioned by you). he needs to be handled firmly with proper explaination. punishment like "no talking" can help if used properly. besides this consistent 'no' to a wrong behavior brings desired results.
indu
