Sounds like she is having a nervous breakdown, you can contact social services, they wont neccesarily take the children away, but may provide help for the mother, they could take them away for a short while until the mother gets herself help, and is lets say back to normal. Social services are there to help, and only take the children as a last resort.
It must be a horrible environment for them to live in, they are probably afraid of there mothers screams (when someone pokes her), its not good, I would act on it now, for the sake of the children...good luck! x