Lares were presumed sons of Mercury and Lara, and deeply venerated by ancient Romans through small statues, usually put in higher places of the house, far from the floor, or even on the roof (but some statues were also on some crossings of roads). Of the Lares proper, there are only two, and they had inferior power. Over time, their power was extended over houses, country, sea, cities, etc., as the Lares became conflated with other Roman deities and protective spirits.
The Genius loci was presumed to take part in all that happened inside the house, and a statue was also put on the table during the meals.
In the early Roman times, in every house there was at least one little statue. Later, a sort of confusion connected their figure with those of Manes, deities of Hades (and the most virtuous dead persons of the family). Finally the confusion included the Penates (other minor deities) as well. In Late Antiquity they represented the "illustrious dead" of the city and empire of Rome, and the Emperor Alexander Severus venerated the Lares of such figures as Abraham, Orpheus, and Jesus Christ.
Historian Cyril Bailey, in his book Phases in the Religion of Ancient Rome, presents some interesting information regarding the Lares. The festival of the Lares was known as the Compitalia, which refers to the crossroads. The crossroads were the traditional setting for the veneration of the Lares. Crossroads have also been associated with witchcraft since ancient times.
Scholar Georges Dumezil, in his book Archaic Roman Religion, mentions that the worship of the Lares included setting little towers with an altar placed before them. Archaeologists Lesley and Roy Adkins note (in their book Dictionary of Roman Religion) that the Lare shrine at the crossroads was “open in all four directions to allow passage for the Lar”.
The ancient writer Ovid, in his work titled Fasti, refers to the Lares as the “night watchmen”.