What happens when black holes collide? | EXPERT ANSWERS PHYSICS GIRL QUESTIONS

What happens when they enter a Bootes void  (from Hanford Ca.) Go Bullpups 
1 . Do they get an instability wobble ?  2 . Do they starve and evaporate  3 . Do they drag the edge of the void with it 4 . Does it aim itself towards material , or turn around and head back