A needle device comprises a housing, a base portion having a mounting surface adapted for application to the skin of a patient, and a plurality of needles. Each needle comprises a distal pointed end adapted to penetrate the skin of the subject, and has a first position in which the distal end is retracted relative to the mounting surface, and a second position in which the distal end projects from the mounting surface. The needles are arranged such that at least one needle can be moved from its first to its second position, or vice versa, with at least one other needle not performing the same movement. In this way a plurality of needles can be introduced transcutaneously at a selected site within the body of a subject. The device may comprise a common fluid conduit with at least two of the needles having a proximal opening to be arranged in fluid communication with the common fluid conduit.