Ear tag ear is tagged. Australian sheep and goats are required to have visually readable ear tags printed with a Property Identification Code (PIC). They are complemented by movement documents supplied by consignors that are used for identification and tracking. Very small ear tags are available for laboratory animals such as mice and rats. They are usually sold with a device that pierces the animal's ear and installs the tag at the same time. Lab animals can also be identified by other methods such as ear punching or marking (also used for livestock; see below), implanted RFID tags (mice are too small
Ear decomposition smaller series-parallel graphs in one of two ways: series composition (identifying one terminal from one smaller graph with one terminal from the other smaller graph, and keeping the other two terminals as the terminals of the combined graph) and parallel composition (identifying both pairs of terminals from the two smaller graphs). The following result is due to : Moreover, any open ear decomposition of a 2-vertex-connected series-parallel graph must be nested. The result may be extended to series-parallel graphs that are not 2-vertex-connected by using open ear decompositions that start with a path between the two terminals. The concept of