Dealing with noisy neighbours

Hello,

I have just become aware in the last couple of weeks of a family having moved in to the flat directly above mine (I'm a tenant).  They have at least one young child who enjoys running/stomping along the length of sitting room and later in one of the bedrooms, and last night I was listening to this from about 8 - 10pm.  I resisted going up to say something because I don't want to make matters worse and they may well be unaware of what can be heard below.

As I see it, my three options are:

1. Approach them personally

2. Drop a note into their postbox

3. Ask the building manager to deal with it

I had a quick look at the building's rules and it does state very clearly that you shouldn't be a nuisance to other occupants but I don't want to start waving rules around just yet.

Any advice about how to deal with this gratefully received.

Corker