@BornOnThe4thJuly
Sorry OP I realise now I asked a stupid question, considering Autism is such a huge spectrum.
My son is verbal yes, he gets very overwhelmed and then seems over excited, then seems to be not aware of his surroundings properly. He ends up scaring his younger sibling, by getting very close and squealing and flapping his hands in her face for example. This happens especially when he first comes downstairs in a morning and when he gets in from school. So I guess it’s the transition that he struggles with.
I have a feeling I referred to your son as female, apologies if I did!
I think you’re spot on with the transition probably being the issue. I can only speak for myself, your son might be completely different, but I know that in the mornings (as an adult as that’s when I started really struggling) my mum knew she couldn’t speak to me before work because I just didn’t have the capacity. We used to just dance around each other in the kitchen like morecambe and wise without talking! In the mornings it may be that he’s coming from a quiet, private space to a noisy space with other people in it. It may seem quiet to you, but he may be sound sensitive. At the other end of things when he’s coming home, again it’s another adjustment to a different environment. Perhaps it could help if he immediately goes upstairs for some time alone when he arrives home?
The flapping and squealing is him self regulating, so there’s clearly an element of stress there for him. There are loads of sensory “toys” available, or he might just want to jump about for a bit. If it was part of a routine where he comes home and goes somewhere quiet and private for a little bit, he could flap and squeal all he wants without scaring his sister.
When he seems not aware of his surrounds, he could be dissociating. He’s just checking out for a bit because it’s too much. I don’t really do this very often, it’s mostly me just going really quiet and staring into space when I can’t be social any more. He might just need “ignoring” for a bit until he comes back around.
I would encourage as much stimming (the hand flapping etc) as possible as it’s really important for autistic people, it helps us regulate our emotions which a lot of us aren’t good at. Ask him whether he wants some scheduled quiet/alone time during the day. He might say no, but he might also be unaware he needs it. I know I only tend to realise I am completely overwhelmed when it’s too late!