Static electricity is simply a build up of charges which can't move. This build up of static electricity is caused by friction and happens when 2 insulators are rubbed together. Electrons are stripped from one of the items and dumped onto the other. This leaves a positive charge on the one which has lost electrons and a negative charge on the one which has gained electrons. This is because it has gained something negative so it has an excessive of negative electrons and vice versa.
For instance in a POLYTHENE rod the electrons move FROM THE DUSTER onto the polythene giving the polythene a negative charge because it has a surplus of electrons and the duster a positive charge because it has a dearth of electrons.
But in with an ACETATE rod the electrons move FROM THE ACETATE ONTO THE DUSTER.
Electrically charged objects attract small neutral objects near them.