Yes they do.
yes
Yes
People drill wells to reach fresh water.
Convenience. That way there is always one within reach. To get maximum tightness use two of the 3 holes.
maybe really small insects or birds that can reach past the spines. They live in there to hide from predators and because of the water source. They drill holes in a side and live there.
by concering many other people in the vally of mexico
You would have to drill about 5,100 kilometers below the surface.
by conquering to people in the valley of Mexico
The 'holes' are impact craters. Some of these can reach a depth of 5km.
Project Mohole took place in the deep ocean offshore of Guadalupe Island, about 200 miles off the coast of Baja California, Mexico. The aim of the project was to drill through the Earth's crust to reach the mantle beneath the oceanic crust.
Just like everywhere else, there are more poor people than rich people in Mexico. Depending on the definition of poverty, it can reach between 47% and 52.3% of the population (some 58-64 million people for 2016).
A really big drill
You're question is badly worded, but sure, in theory humans could reach black holes.