A volcano in Indonesia could be about to blow. It's called Mount Kelud, and hundreds of thousands of people are getting ready for it.
These children go to a primary school in Blitar in East Java. They are practising evacuating their school if they need to.
They also need to know what to do if the volcano erupts before they get a chance to leave their classrooms.
Experts don't know why Kelud hasn't erupted yet. It has more energy inside it now than the last time it blew, back in 1990.
Around 350,000 people live within six miles of the volcano but many don't want to leave their homes and move to shelters.