Imagine living deep under the surface of the ocean in a place that is pitch black, has poisonous gas, and where the water goes from very cold to burning hot. You may not like it, but this habitat is home to some creatures! Tube worms and a special type of clam and mussel are just a few of the animals who live at hydrothermal vents. They are called vent creatures or hydrothermal animals because of where they live.