Here's what we know: There are between 50 and 200 of them. They don't have writing. They don't know how to make fire; observations made by landing parties in deserted villages have concluded that the Sentinelese wait for lightning strikes, then keep the resulting embers burning as long as they can.

What do the Sentinelese eat?

The Sentinelese are hunter-gatherers. They likely use bows and arrows to hunt terrestrial wildlife and more rudimentary methods to catch local seafood, such as mud crabs and molluscan shells. They are believed to eat a lot of molluscs, given the abundance of roasted shells found in their settlements.

Do the Sentinelese have boats?

The Sentinelese hunt and gather in the forest, and fish in the coastal waters. Unlike the neighbouring Jarawa tribe, they make boats – these are very narrow outrigger canoes, described as 'too narrow to fit two feet in'. These can only be used in shallow waters as they are steered and propelled with a pole like a punt.