Free: Contests & Raffles.
While you're at it, mix in a couple of these designs. My multiple catch rates increased dramatically with the double wides with the 2" upper extension and the singles with the extension.
The trap with the rats in it is 6"w x8" tall. The door is 6x6 so when the rat bites the top of the cage (which they almost always do) there is still room for another rat to push in under the first one. All of the traps I make now are this style because of how well they have trapped. My double wides have this also.
I get the 2" extension making it a 6"x8", but wouldn't a 3" extension, 6"x9", make it easier for a rat to push through? I have never built a trap, but plan to after deployment, and I'm thinking if 2" works, then 3" would be just as easy, if not easier for rats to push in.