So my four yo is now the eldest of 3 boy, and has been acting out a fair bit. I've tried a few things, but it seems to me the situation is getting worst and need to find some resources that can help me deal with this.

For a bit of background, we have gone through quite a few changes lately. Over the past 10 weeks, they have had their grandmother stay over for 4 weeks, we have had our third child 7 weeks ago, we have moved houses 5 weeks ago, and he has moved to a new school 5 weeks ago.

I expected him to act out a bit with all this change, but his first two or three weeks were fine.

In the last two, things have gotten worst. He's done a poo in his pants at school, something that hadn't happened for at least 6 months, yesterday he bit another of the kids, and then proceeded to destroy a book the teacher said was hers and very dear to her. He has clearly crossed some new lines.

I've been trying to handle his outburst at home with time-outs. When he screeches back because we are telling him to do something that he doesn't want to do, he has a time-out. Same thing when he hurts no. 2 brother. When he gets out of the time out, we speak to him, explaining what he has done wrong, and asking him to say sorry to both us, and any aggrieved if applicable.

From time to time I also try to get him to express what he is feeling: are you angry? Are you sad? You are sad because we switched off the TV? Because we told you to put your toy down to sit at the table? etc. His reaction is still of a child deeply frustrated by something, and met with slightly animalistic grunts or growls.

So is there anything else we should be doing? Is there a book or website I should look to read to better handle the situation?

Any advice would be appreciated.