If a balloon is rubbed on a woollen sweater it can be made to stick on a wall, this is because the balloon becomes -vely charged when rubbed, when it is brought close to the wall it repels -ve charges in the wall making the wall close to the balloon +ve, the -ve balloon is then attracted to the positive wall. If the balloon is not blown up then it can not be stuck to the wall which led me to investigate the relationship...