I was wondering how many HI’s have come across critters in the plumbing and come to the conclusion that said critters got in through the roof plumbing drain-waste vent? Do you recommend that homeowners put screens over the roof vents?
As an aside: I find it interesting that mobile home plumbing vents have factory-installed caps.
Never seen it personally but have heard a few news stories of snakes coming up through a toilet which is enough to make me want to poop in a bucket instead 
Screening isn’t a bad idea I suppose but I don’t think it’s too common.
I’ve observed tree frogs in plumbing vents, seen a few screens installed on them too (most look like hack jobs).
The house I am inspecting tomorrow, in the seller’s disclosure, is “tree frogs” coming in through the plumbing. So, was considering how they might be getting inside on a 2022, essentially-new, build. Found a few blog articles about frogs and other critters, so want to see how common this really is.
In the frozen north, we only put screens over things that have no chance of freezing over, or when there is an ongoing issue that just can’t be fixed any other way.
Good point. We only occasionally get snow here, so might be safe to put screen over vent.
The vent is a warm spot, so likely just not a problem to have a screen in a non-extreme climate.