In the folklore of the tribes of the Andaman Islands, Lau are ghosts of the dead (They were called Chauga in the language of South Andaman). The Bido Tech Lau or Ti-Miku Lau are jungle spirits, one of the two main varieties of Lau. The other type is the Jurua, or sea-spirits.

Bido Tech Lau are usually invisible, but they can show themselves to the living whenever they wish to do so. Humans who have seen them describe them as fearsome and ugly. They have light skin and long, flowing hair and beards (in stark contrast to the dark skin and afro-textured hair of living Andamanese). The spirits are also said to have small, dwarf-like bodies with elongated limbs.

They live in villages deep in the jungle. These villages are protected from the outside world by impenetrable thickets of Calamus tigrinus (“bido”), a thick cane covered with sharp thorns. Bido Tech Lau translates as “Spirits of the Calamus Leaf”.

The Bido Tech Lau sometimes catch mortals who venture too close to their encampments. If the captured mortal shows any fear, they kill him, and his spirit becomes one of them; but if he is brave, they may allow him to visit their village, keeping him there for some time before releasing him back to human habitation.

A person who has undergone this experience becomes endowed with magical powers. He may disappear again from time to time to visit his spirit-friends for a few days at a stretch.

Bido Tech Lau rarely visit human settlements, but they will attack any person who wanders alone late at night in the forest, making him fall suddenly and violently ill. Therefore, it is always safer to travel in a group. Lau are scared of fire, arrows, human bones, beeswax, and red paint, so these can be used to ward them away if one is compelled to make a solo nighttime journey.