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.
Camel spiders are not even spiders. Like spiders, they are members of the class Arachnida, but they are actually solpugids. Camel spiders, also called wind scorpions and Egyptian giant solpugids (SAHL-pyoo-jids), are only about 6 inches (15 centimeters) long.