Place "calcium carbide" deep in one #1hole.

Cover

Place a lit 15minute highway-safety-flare in the second connecting #2 hole.

Water - SOAK #1 hole thoroughly with hose or bucket.

Leave the immediate area (100 feet plus) - until the acetylene explosion - and permanent extermination of the critter.

Sincerely,
Gargoyle

Works well for skunks under porches, also.