[RowdysMom]

Winkopedia:

A skull and crossbones is a symbol consisting of a human skull and two bones crossed together under the skull. Today, it is generally used as a warning of danger (usually in regard to poisonous substances).
The symbol, or some variation thereof, was also featured on the Jolly Roger, the traditional flag of European and American pirates.

Today, the skull and crossbones is still the only standard symbol for poison. It is, however, less common outside industrial usage than it once was. Apart from its negative marketing effect on environmentally conscious consumers, it may actually attract children due to its association with pirates, a popular toy and play theme. For this reason, in the United States there has been a proposal to replace the skull and crossbones by the "Mr. Yuk" symbol.

The skull and crossbones is also used by the British Army. The 17th Lancers adopted the skull and crossbones as its cap badge upon its creation in 1759, becoming known as the 'Death or Glory Boys'. The cap badge was later used by the 17th/21st Lancers and its present-day successor, the Queen's Royal Lancers who are still nicknamed the 'Death or Glory Boys'.