Stop comparing what would happen to you - it's irrelevant and you've no idea whether they are indeed in contact with schools or social services.
I understand you're worried, but as a result you've not made much effort to do anything about this, so it's hard to blame others when they don't know what's happening.
Phone 101 and speak to the police. They don't tell people who reports to them.
Break it down in the conversation - have notes with you.
Antisocial behaviour is one issue, but it's also got a very dangerous element beyond the bad language - drink or drug driving, unlicensed, probably uninsured, quad bikes on public roads and footpaths, right by a school. Raise it on that basis - safety of local residents and school kids.
If you report harassment, they will have to know who they are accused of harassing. Maybe keep a diary before you report that?
Phone the council. Report unlicensed dog breeding. List your concerns - dogs bring beaten, lack of training, lack of socialisation, not meeting the dogs needs, apparent aggression towards other dogs in the area. Have you found adverts for their puppies? Can you show how many litters they are selling per year?
Also to the council - the antisocial behaviour, including everything you tell the police. Also your concerns about the wellbeing of the children at the address - especially give the recent example of the boy covered in blood, all the quad biking etc.
I assume you aren't the only neighbour? So I'd start with complaints about issues that could come from more than one source. Work your way up to the harassment if you need to.
Keep extremely detailed diaries. This will be your evidence for all of this, but especially the harassment. Noise, words, bikes, violence - all of it. Write down dates, times, names, descriptions of people, clothing, levels of noise, their actions, their behaviour, any drugs or alcohol seen.
Get a big A4 book, preferably one with a binding, write the date at the top of a page and just add lines in to that day when you need to. It's slightly less work that way.