The Constrictor Hitch (also called a Sack Knot, Bag Knot, or Miller's Knot) is used to clamp / fasten a rope tightly around an object. It has a strong, vice-like grip and is hard to untie unless you slip the knot. This knot is similar to the clove hitch in appearance but the Constrictor Hitch is stronger and thus safer.
To Tie a Constrictor Hitch:
Place the end around and behind the item you are tying the rope to.
Wrap the end around to the other side of the object, crossing the standing part.
Continue wrapping the end around the dowel so the end is parallel with the standing part.
Bring the end over the standing part and tuck it under and between the two loops.