Not sure this is the right place to post....Just wondered what the best way to prepare children for an inspection is? What happens if they go all shy and clam up on the day making them look disengaged and uninterested when usually they are bubbly and happy?

Honestly I don't think you can prepare them. You can tell them there's a visitor coming but you won't know how they'll react until the time comes. Any decent inspector should expect that the children might not be their usual selves since there's a stranger there. You will have photo evidence that you can show happy, children engaging in activities if they aren't keen to do this on the day.

Best thing i can suggest is to make no major changes to your normal day to day rountines. Make sure that you stick as close as possible to a normal day in your setting and the children most of the time will respond as they normally do. The inspector will normally be sitting at a table or couch were they can observe you whilst taking notes. If the children dont want to interact with the inspector that is fine because the inspector is looking for how they interact with you and how you encourage and support them in your environment.

I think it comes down to knowing your children, again...
You can get the children involved in introducing themselves and showing the inspector around the house, but if you know a child is very shy and is likely to be nervous of the stranger then try to 'carry on as normal' and don't attempt any radically new activities or ways of doing things. You can ask older children to draw a picture or write a letter about coming to you and they can give it to the inspector. In your SEF you write about the children, or you can let the inspector know on the phone beforehand, that you have a child who may be a bit nervous and the inspector will hopefully be understanding and not be too in-their-face! Inspectors have experience of young children- they know what they can be like! They'll will be looking at how you handle/comfort/support a child who is scared/clingy/nervous etc. It is good to get children used to having visitors- friends and family popping in during your working day as well as out at groups, encourage children to get used to seeing new faces, chatting and basic social skills- not just for inspection-prep but for general PSED.

Very good advice given already. Stick to your normal routine. I did. The inspector is watching to 'see what it is like for a child here'. The children will follow your example. We chatted beforehand about the lady coming to see us. Parents had obviously chatted also as a lo on the school run on inspection morning said 'I'm going to be a good boy today I am'. Then 30 seconds later he said 'have I been a good boy yet?' and all I could think was 'oh, this is going to be a long day!'.