There are people that have been known to live in underground tunnels. These are generally occupied by people who are homeless and who have no where to live.
I would imagine they live same way the above ground people live. lol
a network of tunnels in the ground where a colony of rabbits live.
They live in the ground, unlike squirrels. They also build tunnels to scurry around in.
Ants live in anthills made from mounds of dirt on the surface of the ground, and tunnels underground.
no they live in holes or tunnels they make in the ground
Rabbits live in warrens! It is a network of tunnels under the ground and can sometimes be referred to as a Burrow or in the case of Badgers a Set! Hope this helps!
They live under ground because its better to wiggle around and so they don't get eaten by birds,dogs,foxes, or even people 
Under Ground
they lived in tunnels and caves
Dwarves are subterranean people. They live under ground in hills or mountains.
Ground BeesGround bees are also known as 'mining bees' as they dig tunnels in the ground. The ground bee is small in size and black in color. The tunnels are made to provide shelter to their offspring. For this, they choose well-shaded areas with loose soil and less vegetation. The tunnels contain chambers in the end, made by female bees. These chambers are used to store food for the baby bees. Though they are not aggressive, they can sting. These bees live in separate but close-by nests.I think yellow jackets and underground hornets and gounding bees or mining bees live underground
under the ground