MouseProofing the Prius

Perfect! Air tight now!

 

Get a free cat at the shelter

 

Cats: among the things that turn out to be less free than you thought.

 

I thought it would be the best idea. Can u reach me what I'm not thinking of

 

Hello, thanks to everyone for all of the great information here. I’ve got a 2005 Prius that had a mouse nest in the cabin air filter area so…here I am!

I removed the windshield wipers and upper and lower parts of the cowl with the intention of screening off the openings in the firewall (I think that’s what it’s called? The metal part) as recommended in this thread. However…

It looks to me like the two small openings in the firewall are the water drains for the lower part of the cowl, which in turn lead down left and right towards the fender, which drains down through an opening behind the plastic cover of the front wheels —a potential entry point.

And then when the cowl pieces are back in place, there’s also an opening around the hinges, where the cowls meets the fender, where there seems to be another opening.

If I understand the situation correctly, neither one of these openings would be sealed off by putting a screen on the five main openings (plus two small ones) on the firewall (metal part). This could explain why there are a number of people who put on screens but still have problems with mice getting in—though I imagine the screens are better than nothing.

Does this sound right so far?

The reason I’m asking is because it seems like the only way to prevent mice from getting into the cabin filter area is to screen off the actual vent into the cabin that is behind the metal firewall area (which is, of course, not fully accessible).

I’ll live with mice getting into the cowl area (inevitable I think, with their access to the engine bay), so long as they don’t get into the air intake.

Has anybody tried fitting a screen back behind the metal openings over the actual vent, with any success? First time posting here, thanks in advance!

 

Here is what worked for me. After installing 1/4" mesh under the windshield I still got a mouse nest on the cabin air filter. Obviously I did not get all the entry points. However! I cut out a piece of said 1/4" mesh to fit right over the cabin air filter and snapped it in on top of the cabin air filter. No more nests. It's been about 3 or 4years since I did that and not a single nest has been formed. Mice are not able to settle down on that wire mesh. And the top of that cabin air filter is where they want to be, so preventing that prevents them entry into the car. They may still settle down in other places under the hood, so this method does not address that problem. But the cabin ingress is pretty much only via that filter. Good luck!

 

I’m not sure if it’s different with our Gen 3, but with it AFAIK there’s only one opening into the cabin heat/vent system. I've meshed ours, fingers crossed. Plus the two air exits, at the back corners of the hatch area. For those I ended up taking the rear fairing off (commonly refered to as "bumper", god knows why...) and making little mesh boxes, afixed with sheet metal screws into the plastic frames:



I may be missing something; I did kind of glaze-over, reading through post 205, the various potential egress points.

 

Thanks for both of the replies!

Update: So I put 1/4" mesh across all of the openings in the cowl and over the cabin air filter as well. I left town for a week and unfortunately came back yesterday to find new nest materials above the filter

At this point I've resigned myself to checking/cleaning out the air filter area every couple weeks, especially around this time of year. But if anyone has any other advice for the 2005 model and how to close off possible entrances in the front wheel/engine bay areas, please let me know!

 

Did have the cowl off, cover the cabin air intake opening in the firewall?

That’s can’t be done.

 

So sorry to hear that! You must have rodents that are different from mine. The mesh over the filter was what did it for me. Covering openings under the cowl are necessary, but not sufficient. There are other ways in, apparently. I hope you find the solution eventually. However, I must say that after I installed the mesh over the cabin filter I also found one beginning of a nest, but after I cleaned it out no more occurred. So maybe there is still hope. They try and the mesh makes it uncomfortable, so they stop using that spot. Hang in there!

 

AFAIK there’s the firewall opening (just upstream of cabin air filter), and the two exit openings, at rear corners, below hatch floor.

Not sure how likely the latter is to get rodent entry, but just in case I recent dealt with it, from the exterior: