There's more than one good reason why the Navy SEALs brought a dog with them on the Osama raid (though companionship is important):
"When you're going on a mission," Dowling says, "a raid or a patrol, insurgents are sneaky — they like to hide stuff from you. But a dog can smell them. .... [Think about] Saddam Hussein ... what if Osama had been [hiding] in a hole in the ground? A dog could find that."