Simplify the following text for a Grade 4 native English-speaking person.
Original: The name of Yellowstone National Park 's `` Mud Volcano '' feature and the surrounding area is misleading ; it consists of hot springs , mud pots and fumaroles , rather than a true mud volcano .
Simplified: A mud volcano or mud dome is a kind of volcano that is made by liquids and gases from the earth . There are many different ways that mud volcanoes can be made .