An RFID ear tag comprising a housing 2, a cover 6 associated with the housing 2, a transponder 1 positioned on the housing 2 and between the cover 6 and the housing 2, a washer 3 affixed to the housing 2 and positioned between the housing 2 and the cover 6, the washer 3 comprising means to maintain the transponder in the housing 2, and a second part 7 cooperating with the housing 2 to attach the tag to an ear of an animal.
