Black Holes may be key people in your department or area. So you can't just ignore them, especially if you are in a position of authority. In fact, Black Holes are interested in you precisely because of your stature.
Black Holes are often insecure people who lack confidence in their work, their social prowess, or their judgment. They constantly question their worth and accomplishment. Even if they are intelligent, talented, and resourceful, they don't believe it. So at every stage, they ask you to check their work. Every project requires more time and takes you away from your own work.
Black Holes often question whether they are accepted among their peers. The fact is that people distance themselves from Black Holes to avoid their clinging behavior; their fear of rejection is a self-fulfilling prophecy. Black Holes feel isolated and worry about their work relationships rather than their work.