Abstract: Tongs, in particular for mounting ear-buttons on animals, comprising a first lever and a second lever each constituting a handle and pivoted together, a first jaw and a second jaw actuated by the levers and each provided with a device for maintaining a part of the ear-button and a return spring for biasing the jaws to the open position. The first and second jaws are connected to the first and second levers by a mechanism for maintaining the jaws always parallel. It further comprises a rapidly actuated device for opening the jaws when the first and second levers are moved toward each other.