Growing up in northern NY we couldn't use colony traps. Not sure if that's changed but up until 1981 that was the rule. Then where I lived in eastern Washington I had some rats but not in great numbers and not where I felt a colony trap would work or be advantageous so I never developed much for knowledge on them.

I've built several sets of the standard colony traps, 6, 7, and 8 inch that nest. They are all 24 inches long. I have built several 36 inch funnel traps because I've seen those built by guys on here. I have ended up with 100' roll of 14 gauge, 1"x2" mesh wire and wondered about making some of the standard square colony traps 3 foot long. I know finding a run straight enough to accommodate one that long might be a challenge but seems like they might work well in culverts or ditches. Some irrigation ditches are narrow and string straight for hundreds of yards. So do any of you colony trap guys use the standard square colony traps in lengths longer than 2 feet?

Since I'm not able to trap this season I have a lot of projects to work on to keep me busy and one project leads to another. And I'm always thinking stuff up. Once I'm able to trap again, I plan to travel some to where I can do some spring rat and beaver trapping.

I don't see why not... rule with fish/eel pots is the bigger the better... IF..you have the body of whatever to fill it up... otherwise you can set more locations with the smaller pots...

and no, still can't use colony traps in NY

What does your state trapping regs allow for colony trap size?
In Wisconsin, colony traps have a maximum size of 6.50" square or round by 36.50" long.

I’ll recheck the regs but I don’t recall a size limit or restriction on colony traps.

No restrictions on colony traps in my state.

No restrictions here either.

I think like with everything trapping, it's nice to have several tools in the tool bag. If you got into good rat country and could find a place to set them, you'd probably need help lifting them out of the water. If you have the material to make them, I'd make a half dozen, maybe a dozen, to have on hand just in case. When rat trapping, if you have the spots to use colony traps, you can't beat them. Always nice to pull 4-5 rats out of the water vs. 1.