Im worried about a neighbours child what should i do?

hi im so worried about a neighbours child and dont no what to do, the child is six and is sometimes left out in the street till around 10.30pm at night, her mum always has friends round plays music late into the night and consumes a lot of alcohol around 3 to 4 nights a week, ive also noticed that the child misses school alot and is often out playing when she should be at school, i have also heard the mother yell abuse at the child and call her names such as 'a dozy bastard and an ******* moran' ugly tramp and a wee witch/***** these are just a few of the things ive heard what do i do do i report her and if so to whom, i have a 4 yr old daughter myself and would never dream of behaving in such a manner