 An elaborate system of predicting good and bad omens based on the sounds made by geckos, their movement and the rare instances when geckos fall from roofs has evolved over centuries in India.In some parts of India, the sound made by geckos is considered a bad omen; while in parts of India, Assam, West Bengal, Bangladesh and Nepal, it is considered to be an endorsement of the truthfulness of a statement made just before, because the sound "tik tik tik" resembles the expression "thik thik thik", which in many Indian languages (e.g.Bengali) means "right right right", i.e., a three-fold confirmation.