Neighbour one, I'm afraid....

So - next door have 3 boys, aged about 7, 5 and 2 ish... They're ok neighbours, we don't chat much or anything but we're polite.
We both work full time, have 4 dc between us, 7, 8, 12 & 15, and we try and get a bit of a lie in on a weekend if we can, I get up at 6 every weekday, and if we're lucky, we get to lie in until about half 8 at the weekend, it's glorious.
However.... as soon as the weather gets warmer, next door neighbours let the dc out to play in the back garden between 7 and half past. They're really noisy and have loads of really loud toys, electric ride-along stuff, you know. I had forgotten this happened last year, and it pissed me off then - I remembered with clarity this weekend 
So what do I do? Do I put a note through the door like a yellow bellied coward? Or do I knock and ask them to be a bit more considerate? Will they look at me like this?
AIBU?