When electrons are transferred from one material to another due to friction between the two different materials, static electricity occurs. The electrons negative and positive charges attract one another and the two materials consequently cling together hence the term static cling.
In order for static cling to happen, three conditions need to be met. First, there must be friction between two materials. Second, the materials must not be the same, but must be electrically insulating. Third, there must be dry conditions with humidity at very low levels, an environment which is conducive to electron transfer.Learn more about Electricity