Attic subfloor, venting, and mice

Question

I am trying to evaluate what my exterminator/remediation company is telling me, and would like some help, please.

I recently added a subfloor to my attic. I sought advice from a contractor I know, and used 4'x8' sheets of ply, with some of that subfloor glue, ringed nails, etc. It really changed the attic from a completely unusable space into something that provided good storage.

For as long as we've lived in the house, there have been mice in the attic. As far as I can tell, it's never more than one, and honestly, it usually ends up getting caught in a trap or just dying up there. I assume they enter through the modest gaps that also provide venting to the attic, but I can't say for sure. I don't go up there much - storage, again - but when I do, there's often a dead mouse for me to dispose of.

A while back (6+ months ago), we had a rat, though. And it was big and bold and noisy even. It rummaged around in the walls, making its way to the kitchen. It didn't particularly seem to care that we knew it was there. It eventually even bit my kid. (It is now dead, and the home is rat free.)

Anyway, after that, the regular pest control company I was with sent someone over to help point out remediation activities we could do, like better sealing the garage, removing the holly tree that was super close to the house, etc. I've since hired a different firm (because cost and their focus on remediation first) and they would prefer to completely remove the subfloor, pull out all of the old insulation, completely treat (not 100% sure what that entails), then put in new insulation, and leave the attic as just studs and insulation again.

I do want to treat and I would prefer to make my house as rodent proof as possible. But the idea of taking the subfloor out of the attic is tough to swallow, and not just because of cost, either. I hate the effective end state of the attic being so much less useful to us all.

My main questions are:

1/ Is this really a standard course of action when treating for a modest number of mice?

2/ Is this the only course of action for an attic?

3/ Understanding that an attic is supposed to be somewhat vented, how does one deal with the venting also being the likely access point?

Answer 1

I don't know what is "standard" remediation for a pest control company, but preventive exclusion will always be the most effective solution.

I had mice in my attic recently... they will start gnawing on something in the ceiling in the middle of the night, the noise would wake me up and make it difficult to sleep.

I put out snap traps, the green poison blocks, a smelly repellent, and even a bucket of death. The snap traps caught a couple and I could see that the poison was being taken. But the problem remained.

There are no trees near my roof line. I did put some strainers on the downspouts to prevent potential climbers in there.

I finally got out my ladder and with an inspection mirror, began closely examining the ventilated drip edge on my roof. I started looking at the corners and joints hoping to find some sloppy meets between two pieces. I stuffed steel wool in any suspicious small gap. But nothing seemed likely, until I found one side where the gutter was not holding the drip edge against the soffit boards. There was a good half inch+ gap where a small animal could just enter the attic directly. I got some sheet metal screws and secured the drip edge to the house. Soon after the nocturnal noises disappeared. Though sometimes I hear something which might be the mouse in the gutter trying to get back in.

Seriously, make sure nothing can get in and you won't need all that other stuff.