I also have it in my policies that sometimes a child needs to remain at home because they need extra love and attention that they can't get in a group setting. I can't remember how it is written. But if they are inconsolable and clingy they need to remain at home. Luckily the parents I have right now understand this and want their child home with them when they need that extra love and attention. It is usually right at the start or end of an illness where there aren't really any other symptoms aside from them just being 'off'.

We've all felt like that and the last thing you want to do when you feel lousy is to try and keep up with 4 happy, energetic kids (even if they are your friends).