The House of Representatives is entitled to a doorkeeper and a messenger who shall perform such duties as may be required of them, who shall be elected as provided for the election of the Clerk of the House of Representatives, and who shall be compensated as provided by resolution of the House of Representatives. The Senate is entitled to a sergeant-at-arms who shall perform such duties as may be required of him, who shall be elected by the Senate, and who shall be compensated as provided by resolution of the Senate.