Abstract: Tatooing pincers for marking ears of animals by injection of tatooing liquid. Pincers comprise a support and first and second jaws. Second jaw carries a number of hollow needles protruding to first jaw. Second jaw is yieldably connected to a drive by an intermediate part comprising a pump chamber connected with the hollow needles. The volume of the pump chamber is reduced when intermediate part yields under increased pressure after needles have fully penetrated animals ear between jaws, and tatooing liquid in pump chamber is injected via needles. Thus increased pressure provides for cleaning of needle holes from particles of skin resulting from penetration. Tatooing liquid is sucked into pump chamber from a storage chamber via check valves. A pneumatic drive may be used to facilitate operation.