Behaviour blues

I have worked at a private day nursery for nearly two years. In that time I have been scratched, head-butted, bitten, kicked, had a chair thrown at me and taken abuse from the children, who are aged between two and five. My colleagues and I find it really difficult to go to work each day wondering how many bruises we will receive while trying to help these children. But we are unable to sanction them because it seems that everything schools and nurseries used to do to chastise children is now illegal.