Needles and methods of plugging a needle having a tip opening with an inside diameter and a needle tip length, wherein the methods generally comprise the steps of, providing a plug material having a predetermined viscosity; providing a delivery device for introducing the plug material into the needle tip opening, wherein the delivery device comprises a delivery tube having a delivery diameter that is equal to or less than the inner diameter of the needle tip opening; introducing at least a portion of the heated plug material into the needle tip opening via the delivery tube.