Thaipusam is celebrated during the Tamil month of Thai, which coincides with January or February, on the day on which the star Pusam appears. Each year since 1892 the festival has attracted crowds of devotees and onlookers to the immense limestone Batu Caves, and recently annual attendance has approached a million. While this is clearly a popular event, those of a squeamish disposition are unlikely to appreciate the main attractions.

After sunset the first pilgrims, having ritually cleansed themselves at a river two kilometres from the caves, arrive at the temple to pray and leave offerings such as milk or honey. Many are in trance-like states and pierce their cheeks or tongues with metal skewers of up to a metre in length, which are said to represent Murugafs vel. Others strip half-naked and attach hooks to their torsos, from which they suspend colourful fruit or flowers. But none of these shows of devotion can quite match the dreadful panache displayed by the kavadi bearers.

Kavadi is a word used to describe all manner of wooden and metal contrivances that are attached to the body of a devotee with chains, hooks and needles. The heavy, birdcage-like kavadi are adorned with colourful feathers and flowers, and clearly sap the mental and physical reserves of their carriers. In heady trances they dance the two kilometres to the foot of the caves' 272 steps in vicious twists and twirls, chanting incoherent songs and incantations and inspiring awe in observers.

Onlookers who brave the crush up the temple steps and make it to the interior of the caves will witness perhaps the most remarkable aspect of this festival - the apparent lack of blood or lasting discomfort. Visibly exhausted pilgrims are brought out of their trances by priests, and their skewers and hooks are removed. White ash applied to the previously pierced area magically stems all flow of blood and numbs the pain, and after a short rest most participants melt away into the crowds thronging the procession route.