The state legislature is constitutionally-mandated to meet for 125 days every four years and 90 days in other years. The Mississippi Senate has the authority to determine rules of its own proceedings, punish its members for disorderly behavior, and expel a member with a two-thirds vote of its membership. Bills must undergo three readings in each house, unless two-thirds of the house dispenses with the rules. Amendments to bills must be approved by both houses.