To pull DS from his school

@FoxyDash is his father in his life? Or a positive male influence? You haven’t specified.

You are blaming absolutely everybody but yourself for this.

OP you come across as a parent who minimises their child’s behaviour as ‘not that bad’. Whereas a lot of parents (mine, for instance!) would have been mortified if I had ever behaved like that.

There are quite a few teachers on MN (past and present) and i can guarantee that they read your post and rolled their eyes. That behaviour is some of the worst to deal with because it disrupts the learning of everyone else and takes teachers away from what they should be doing- teaching. But, according to some parents, it’s “not that bad”.
It is bad. Your child is rude, disruptive and disrespectful.

There has also been some good advice and additional questions from PPs that you haven't responded to. Something is driving the behaviour, and behaviour is communication. If you get to the root cause you stand a better chance of supporting him. Changing schools may just end up passing the problem on, which doesn't actually help your son.

Why wasn’t he going to be doing PE?

Look at different schools and do a managed move.

Thanks.
You really need to work with the school and address his poor behaviour and maybe get him some counselling to find out what has caused his behaviour to deteriorate to such an unacceptable level.
The behaviour you are describing is really bad, even the things that you say are low level are extremely disruptive and unacceptable and the throwing of stuff, fighting and vandalism are outrageous.
Are you putting consequences in place for him at home? Have you asked him why hes behaving this way?
What are you doing to support the school?

You say he was fine in primary, so do you mean that this behaviour has been evident from Y7, or more recent than that? What is home life like for him, has there been any trauma? What about his online habits? Who does he socialise with? What are his personal relationships like?

If you can rule out all of the above, and your other children are doing well with your behaviour management strategies, then it may point to something more neurodevelopmental. Undiagnosed nd kids often fall apart at secondary school unfortunately, and if it's something like adhd then unfortunately many schools are not good at spotting it or dealing with it effectively precisely because they approach it from a perspective of behavioural choice.

The issues you describe are not low level and I think you need to wake up to how bad it is. 14yo ds was diagnosed with adhd last year. His behaviour points were for low level things - chatting to friends, not producing enough work, missed deadlines, swinging on his chair, forgetting equipment. If he'd reached the level of disruption you describe, he'd probably have been diagnosed sooner... you have more than enough evidence to ask them to support a referral.

I couldn't agree more.

OP, if you haven't already, could you request a meeting with DS's teacher and head of year to discuss SaLT intervention.

While I understand some of the behaviour you have described is dangerous to other students, and the school has a duty of care to keep others safe, isolation is only a short-term solution to the immediate issue. It doesn't fix the underlying problem. There is a cause for his behaviour.

So he "isn't much better at home" yet you are blaming the school for everything? If his behaviour is the same wherever he is and your only problem is that you don't like the way school handle it (because his sister is embarrassed), the implication is that you don't think he should be punished at all (for what is certainly not "low level" misbehaviour) and that you don't actually do anything at all about it yourself. It's very noticeable that you haven't answered any of the many questions about how you handle it in general. What do you actually do about it?
Your constant comparison of him to his sister(s) very probably doesn't help, either. Did you not want a boy, OP? You really don't seem to have much real interest in him beyond the fact his reputation embarrasses his twin.
Go and see the school and ask them how they propose to help him and how you can help at home. Don't lead with "or I might have to remove him" - they would probably like to see the back of him.

So what do you think a suitable punishment would be for not getting changed for PE?

The behaviour you describe isn't low level misbehaviour.

What are his results like in tests and assessments? I'd be concerned that he's acting out because he's struggling to access the curriculum - especially if GCSEs are on the horizon.

If I were you, I'd make a plan of things to check:

Eyesight and hearing - can get both tested at Specsavers.
Assessment by Educational Psychologist. Ideally this would be done in conjunction with school so they have buy-in, and be more likely to support any changes/adaptations that are needed. He may be struggling with dyslexia, processing issues etc. A lot of these things can go undetected in bright children, who only start to struggle when work gets harder and they can no longer wing it.
Check his phone - any signs of bullying/accessing inappropriate content online/being drawn into county lines etc.

If all of that comes back fine, then consider whether there might be some ND. The Ed Psychologist might have something to say about this too.

If your son has a happy, stable home life, friends, hobbies - then there will be something else going on. You just need to find out what it is.

If people dont have a child like this then they have no clue. My 14 year old is the same as your son. But is on the adhd pathway.
We are currently in the process of doing an in year transfer to move high school as he is heading for failure at the school he is at.
The school is known to be very strict and we thought this would be good for him
What has actually happened is he gets himself worked up before even going into school, ends up acting out, feels like he needs to be silly to keep friends, the teachers then punish him and he retaliates .
He thinks they all hate and dislike him so no point in trying anyway.
The school have changed their behaviour system to instant detentions , no warnings. But the detentions are at break and lunch. My son desperately needs this time to blow off steam .
He is given a detention multiple times a day to the point where every break and lunch is spent in a detention causing a vicious circle. I have had many meetings with his school. He has a classroom support plan which is not followed by some, and they refuse to consider different punishments , he would rather go in isolation to decompress.
Its stressful for the staff, him and us and I have almost daily phone calls. He's only got 18 months left until he finishes school forever and I honestly can't wait. Its been a daily struggle since he was 4 years old.
I have other children who are completely different, compliant and excellent at school. Its horrible for everyone involved and I send you love and support

From what I've seen there are only a few "nasty judgmental" posters. The majority has told OP that her son needs help.

otherwise he is going to continue to run rings around you

He sounds like an unhappy boy who is not coping and who is struggling with his peers, rather than one who is playing the system and winning.

I would try loading him up with caffeine in the morning and seeing if that calms him down.

It’s intriguing to me how sow many posters are preoccupied by the idea he needs a ND assessment. If this is a sudden change in behaviour and he has shown no previous signs he is unlikely to be ND. Parents often claim ND in their kids to avoid parenting them.

He needs both! Someone needs to get to the bottom of the cause of his behaviour and then help him to address it. But he can't be left to carry on misbehaving without consequences in the meantime. The OP seems to think walking out of class is 'low level', well there's part of the problem. If that is being disregarded as low level then he clearly doesn't have any strict boundaries and structure. The OP also seems to be relying on school to sort this and claims that it's not her fault/problem because her other kids are fine. Where is the parenting? The school system is there to help but the responsibility lies with parents.

”he has no incentives to behave”

You mean like the other kids in his class/ year who understand what the expectations are? What incentives does he need ? Cash ? Praise for not ripping up books and not starting fights? Special dispensation to storm out of class and disrupt other pupils learning with his not low level poor behaviour and attitude.

By all means pull him out of school , but you would be better engaged talking to the school and maybe getting him moved to a PRU where he can continue to learn because otherwise he is going to continue to run rings around you.

Not an expert but it seems likely there's something underlying this behaviour. Maybe get a private assessment done for ADHD etc. Also maybe some kind of counselling? Lots of children seem to mask/cope in primary school, but struggle to adapt to secondary for whatever reason.
Would your boy talk to someone?
See @Lemoncake1991's answer really.

I can see why you are concerned about the impact on your daughter but I do think your sons behaviour is very concerning. The things you describe are significant. Presumably he's fully aware of school rules and expectations so he's choosing to flout those or he just can't comply. That's the part that needs investigating and I would go into school, apologies if you have already and see what they suggest. I think my focus would be him rather than your daughter because he's on a tricky path.

SENCO and SEMH specialist here. I agree with PP this is not low level, your DS is clearly struggling with something in the school environment. This is actually very common pattern with movement to secondary school which can take a couple of years to reach a head. Mainstream secondaries are big, intimidating places for some kids. I wouldn’t say he definitely has ADHD/ASC but there are some flags in your posts and irregardless of diagnosis he is struggling and this warrens further investigation. Has he ever had any psychometric assessments ? How’s his working memory, organisation, ability to maange a list of instructions? Difficulties in these can indicate excecutive functioning difficulties which CAN be indicative of ASC/ADHD (but isn’t always!) Has the school and yourselves done a long Connors report?

EP hours and support are very very low in mainstream. No fault of anyone’s other than the national shortage of EPs. If you can afford private I would encourage you to consider this, and as they do a range of psychometric testing including the BRIEF. If your area has a specialist teaching team I would ask for a referral for your DS to the SEMH team or equivalent. Speak to the SENCO and pastoral lead

This all been said, he does also need consequences for his behaviour, his needs could explain it but not excuse it. What are his aspirations, does he have friends. Try to help him find the words he is communicating with his behaviour. Try to work with the school, his behaviour is not low level and will be disruptive to the learning of others, and the sanctions will be similar in most mainstream settings IME. Good luck OP

This - I think you need to research adhd and autism. My girl/boy twins never had problems in primary or high school - but both were diagnosed in mid high school to end of 6th form.
This child is acting out not acting up - he’s clearly having trouble processing his emotions which is a trait of ND.
ND is a spectrum and it’s high school where kids traits show up the most as it’s very overwhelming with different classes / trickier friendship groups / raging hormones.
Most twins are not full term and increased chance of ND especially if you had c section or steroids when pregnant.
Neither of my twins schools referred them for ND testing … they were perfectly well behaved at school but struggled at home. But when their teachers filled in the forms, its was the results of their teachers forms which effectively secured their diagnosises.

Is he Year 9 or 10?

Has this been a recent development or has he always been difficult with school?

Have you asked him why he behaves like this? Is there something going on that makes him think he can do as he pleases? If he's Year 9 is he fed up with having to do subjects he won't choose for Options and acting up because he's bored and frustrated? What's his friendship group like?

I agree with others that you need to be focussing on your son - this kind of behaviour can have all sorts of causes from special needs to much darker stuff - but it's very difficult to address once the ball is rolling nhs and can often go downhill fast.

As for his sister - no one will be judging her based on his behaviour, they will just be relieved she's not doing that same things!