Picking up a rat colony tomorrow. Have a question.
 

So my feeder supplier is getting out so he can travel and do stuff with his wife. Happy for him, but sad for me lol. He's selling me what he has left of his breeding setup (An ARS 70, 6 high rack, with watering system, 50 rats, gas chamber etc.) I initially was planning to put them in my garage as it doesn't get too cold in winter, and I can use a swamp cooler on the really hot days... Well I thought of a potential problem. Will loud noises be a detriment to the colony? I keep my riding mower in the garage, and I also do wood working, welding and other fabrication in the garage as well. I was wanting to hear from people with more experience with rodent colonies (I've never kept more than 4-5 females at any point).

The benefit of using the garage instead of the basement was the obvious benefit of not smelling rats, and also the upkeep will be far easier in the garage, cleaning tubs and disposing of dirty bedding.

Not sure this is relevant, but I'll contribute it anyway.

I raised rabbits for about ten years (just ended that project recently, actually). I kept them in a large lean-to addition on a detached garage. The first year I had them, the does killed nearly every litter they had. I finally figured out what it was: I also stored firewood in that addition, and I would haul the bucked logs to near the shed, then split them with a maul and stack the splits inside. Once I started splitting in the woods before hauling the wood back, the killing stopped. It was the sharp repeated noises.

The rabbits always tolerated the noise of our tractor without issue.

That is good information to have, I definitely don't want to cause issues with the females. I have read that stress inducing noise will cause mice to eat their young, but haven't found info regarding rats. I may just have to play it by ear, see how things go, and if necessary I can haul the mower out and start it in the drive.

So I've had the group now for a week. My riding lawn mower appears to have induced a premature labor in one female, resulting in her dropping 3 quite small pinks. (2 of the 3 didn't survive). Other than that one issue, it doesn't appear to be a problem keeping them in the garage. I will definitely be moving the riding mower out next year (thankfully I only have maybe 1 more mowing for the season).

So far, I'm most surprised by how little they smell (the rats themselves). I figured a group this large would be fairly stinky by the end of the first week but they weren't. The only off putting smell is the mazuri 6f feed. My wife and a couple of the kids find it rather repulsive.

I wonder if maybe the move itself contributed to the female's trouble. That's pretty stressful, I'm sure.

Many people think rats smell much less than mice. I think they mostly smell different; maybe personal sensitivities play into it.

Anyway, it sounds like it is going well so far. :)

Thought I'd post an update. They are going well now, I will be building a 2nd rack using Super 70 tubs (have a 2 high grow out I built previously, but don't think it'll be enough.)
They are doing great in the garage (knock on wood)