In commercial and everyday use, the term weight is usually used to mean mass, and the verb to weigh means to determine the mass of or to have a mass of. Used in this sense, the proper SI unit is the kilogram (kg).
For other uses, see Aphid (disambiguation). Aphids, also known as plant lice and in Britain and the Commonwealth as greenflies, blackflies, or whiteflies (not to be confused with jumping plant lice or true whiteflies), are small sap-sucking insects, and members of the superfamily Aphidoidea.
Size relative to a tea cup: Scorpions are members of the class Arachnida and are closely related to spiders, mites, and ticks. They are commonly thought of as desert dwellers, but they also live in Brazilian forests, British Columbia, North Carolina, and even the Himalayas.