I have a Giant Rat running around in my fortress eating my stores and drinking my drinks (kind of like a new peasant, actually). How do I get my dwarfs to drop what they are doing and just massacre the thing?
Assuming you have some dwarves assigned to a squad already you just need to issue a kill order to the squad. First open the squad menu with s, select your squad by pressing the letter next to it. On the squad menu, press k to issue a
kill order, then l to list enemies, move to the rat, and press enter. The squad will automatically move to the rat and attack it.