Abstract: An improvement for use with a conventional ear identification tag of the two-part type where a "button" is inserted through the ear of the animal to engage a "boss" from which a depending identification tag is attached comprises a press-fit retaining ring attached to a hollow housing for attachment over the boss of the ear identification tag. The housing may be used to house and dispense insecticide, insect repellents, drugs and the like, or it may be used to house a miniature radio transmitter or transceiver of the type frequently worn by animals, such as dairy cattle. The housing and/or the attachment means may be made of frangible material to permit quick removal when the material in the housing is used up or no longer is necessary, or where replacement with a new housing filled with insecticide, insect repellent, drugs, or the like is desired.