Alright you have conned me out of it. The gruesome way we eliminated a BUNCH of rats when I was a kid.
Warning not for the FAINT of heart!
First you acquire a barrel nice tall trash can will work. The you put it in a likely covered location with a 2 X 2 or other nice long stick inside and another 2 X 2 or stick outside and braced so that it is sturdy and won't fall down. Then add some grain to the trash can and leave it mostly alone for a few days. This is to enable all of the rats to find the free food and invite their family and friends to the feast! Be sure the boards are set up so the rats can easily enter and exit the barrel.
While you are waiting fashion a board or circle of sturdy wire (or even the lid off of a smaller trash can with a few holes in it) that will slid down into the bottom of the feeding barrel.
After you are good and sure that the rats are all coming and going to your feast remove the inner stick. The rats will leap down into the barrel to eat and be unable to get back out.
Now the next step has options. Some just remove the stick and get the barrel full of live rats (this is what we did) and some fill the barrel with a foot of water and add oiled bran to float on the surface (this works too). Water method they plunge into the water and begin to swim till they can't swim anymore. With a rat this can take 72 HOURS! With the dry method you wait until you are full of rats, then add the water to about a foot or two deep, then add the follower (your other lid) and weight it to submerge all of the rats at once. This way they drown in a few minutes.
After I weight it, I leave for a while, then come back and dump out the carnage.
You have to either move the trap a bit or wait a while or both before this will work again. Rats are smart.
Good luck and happy swimming!
)
What is the broom for? 
