heir and without providing for the adoption of a son in his will, he could have a son assigned to carry on his family. An adopted son was no longer a member of his original oikos, but was transferred to the oikos of his adopter. If he wished to return to his original oikos, he had to leave a son of his own in his adoptive oikos in order that it might continue. Pets Some animals were kept in the home from at least the time of Homer, who mentions dogs. The most popular pet was a small dog, often represented on 5th-century BC Attic gravestones and vases. Adultery If a married woman was caught committing adultery, her husband was required to divorce her. Additionally, any woman found with a moichos (adulterer) was barred from public religious practices, as well as from wearing any ornament. Lysias' speech On the Murder of Eratosthenes offers two possible reasons for the concern of Athenian men with moicheia: firstly, that the seducer not only damages a woman's chastity, but also corrupts her mind, and secondly that a clandestine relationship brings into question the paternity of the woman's children. Christopher Carey considers that the second reason given, the bringing into doubt of the paternity of children, was the more important consideration, as not only was the paternity of children important for inheritance, in ancient Athens this inheritance involved the cult of the family's ancestors, making the purity of the blood even more important than it might otherwise be. Finally, adultery was feared because through seduction, unlike through rape, an adulterer might gain access to the household and its possessions. Modern sociology The term oikos is contemporarily used to describe social groups. Several dozen to several hundred people may be known, but the quality time spent with others is extremely limited: only those to whom quality (face-to-face) time is devoted can be said to be a part of an oikos. Each individual has a primary group that includes relatives and friends who relate to the individual through work, recreation, hobbies, or by being neighbors. The modern oikos, however, includes people that share some sort of social interaction, be it through conversation or simple relation, for at least a total of one hour per week. The term oikophobia is used to refer to fear of the home or of household appliances. It has been extended by the