There are many animals living underground. Most of them appear regularly. But not a cicada. It is an insect that only pops up from the ground every 17 years!
When the time is up, they will be thousands at a time. This is happening in the United States. The cicada is looking for someone to mate with on the ground.
After success, they will lay eggs and die. After the eggs hatch, the larvae quickly disappear into the ground. Then they only reappear 17 years after adulthood.