What kind of range do those have, and what did you shoot them out of?
Out of a .22. I actually have my grandfather's old Remington smoothbore .22 single-shot bolt-action (the world's smallest shotgun, basically), but you can shoot them out of any .22, long gun or handgun. They also make really good snake loads.
But they don't have much range - maybe 15 yards, max - I snipe the squirrels from the kitchen door when they get to be too numerous. The main advantage is that you don't get any significant ricochets - they use 12 shot, which is tiny.