Earthquake

An Earthquake is a naturally occurring game mechanic in Caves. They occur semi-regularly but can be induced with explosions. Earthquakes cause rock type items to fall from the roof of the Cave. Some items are renewable only through earthquakes. When the items hit the ground, they have a big chance of shattering on impact, which means they cannot be obtained. The items that can fall are:
 * Common(75%),
 * Rare(20%),
 * Very Rare(5%), ,

Earthquakes can be very dangerous, as the falling objects can hurt the player. When an earthquake begins, the camera will first shake, the character will give a warning, and then things will start to fall. Then, each object creates a round shadow on the ground, which lets the player know where to go to avoid getting hurt. It isn't safe to stand where something is falling until it has stopped bouncing or has shattered. Earthquakes will also destroy walls and some other structures over time if items land on them.

After an earthquake occurs, Slurtles and Snurtles will spawn out of Slurtle Mounds and feast on rocks and other materials that fell during the earthquake. Once an earthquake starts, all Splumonkeys will return to their Splumonkey Pods.

Trivia

 * Earthquakes were added in the Underground update.
 * This has made all the items listed above renewable, besides Gold, Blue and Red Gems. Those were already renewable, although they're more readily available.
 * In the older versions of Don't Starve, Birds in cages, Chester, and presumably Pigs stayed asleep underground even during earthquakes.
 * Earthquake drops will damage anything they fall into including mobs and walls.