I had a big war with an ant colony that once invaded my room. It was a long and hard battle that stretched over several days, but I finally defeated them with nail polish (to seal off the holes they came from) and tons and tons of ant spray. They held a big council behind some drawers on the wall - hundreds of 'em - and I just sprayed the whole darn thing. There's still a stain on the wall today but at least the war was won. Also, ant traps. Love 'em.