Neighbors are constantly running and screaming?

Are you living in some sort of unit or apartment setting? If so, I would advise you to politely make your complaints known to the residents of the downstairs apartment. If they do not listen and continue to be disruptive, you have one of two options. Firstly, you can see if their noise is causing concern for any other neighbours, and if so, you could ask these neighbours how they would feel about making a complaint. Secondly, you could simply go to the housing body (most apartment dwellings have a body that will determine costs such as gardening, maintenance to driveways, fences etc.). If you decide to do this, write down what you have seen or heard in simple terms, so that it can be understood (I would also advise typing instead of handwriting as this looks neater) and lodge the complaint. If it continues, get the police involved. If their noise is continuing through out the night into ungodly hours at which you or your neighbours are asleep, you've got a right to do so. Best wishes.