6 months ago my 3 yr old son starting hitting, yelling, spiting, back chatting & will not listening. I've tried everything from naughty chair, taking toys etc off him, smacking him on hand, getting down to his level of eye sight & explaining NO you should do things like that or NO your not having that but nothing works. I spend a lot of time with my son doing different actives & he still will go off at anyone who has my attention. He doesn't like to share me with anyone. He has 2 older half sisters 13 & 15 yrs old who recently came to live with us & his grandmother who was living with us passed away a month ago. His father works away 2 weeks & is home for 2 weeks. Is this normal behavior from a 3 yr old who's life has changed & having his father work away from home 2 out of 4 weeks.