Not many foreigners would know that the "Express Train" is the nickname of the Bamboo Caterpillar (Omphis guscidentalsi family Pylalidae), and one of the most famous souvenirs from Chiang Mai.

Bamboo Caterpillar is the baby of a species of Night Butterfly that can be found in the beginning of the winter season only (around October each year). The worm has to alive inside the young bamboo for 10 months and eats cotton wipe for nourishment. This way they will grow together with the bamboo they live within. This kind of worm can only be found at the Bamboo Forest in the Northern Part of Thailand, at a level of 480 - 1300 metres from sea level.

How to eat: Famous recipe is deep fried with a bit of salt, where it will become crispy and taste great. Do not be concerned with the cleanliness, bamboo caterpillar is very clean because they live inside the bamboo protecting them from the outside, and they only eat bamboo cotton wipe. There is about 26-29% of protein and about 50-54% of fat, and 100% from nature!

The last thing one should know is Express Train is not cheap, and about 200 - 300 Baht/kgs fresh from the forest, and when it is fried, the price would be even higher.