Yes. The nearest known black hole is about 3,000 light years away in the system V616 Monocerotis. There is a probably supermassive black hole at the center of the Galaxy, about 26,000 light years away.
Black holes are not present in the center of every galaxy, but many galaxies, including our own Milky Way, have a supermassive black hole at their center. These black holes have a gravitational pull so strong that not even light can escape from them.
No. There are estimated to be dozens or hundreds of black holes of various sizes in our galaxy, and billions in the universe as a whole.
Black Holes' can 'eat' any type of matter in the Universe.
Yes, it is possible to have holes in your yard without any mounds present. These holes could be caused by burrowing animals or other natural processes.
no
No
no
Not every galaxy has a black hole at its center, but many galaxies, including our own Milky Way, do have supermassive black holes at their centers.
No.
At any time.
Black holes
There is no proven connection between the Bermuda Triangle and black holes.