I had a Gen 3 prius, and last year I had mice enter the car. Apparently the design of the Gen 3 gives the little buggers a highway right into the cabin compartment. They come right in thru the ventilation system, and drop off in the glove box. I switched to a Prius Prime in October of this year, and when I opened up my glove box two days ago, Imagine my shock at seeing shredded paper, mouse droppings, and a little hollowed out Acorn. (Nearest Oak tree is over 1000 feet away from my car). Looks like the same pathway exists for the Prius Prime. FYI, the little mouse repel packets (Mint Oil, Ceder Oil, Rosemary) don't work. The mouse actually chewed the less than 2 day old packet trying to make bedding. I called an exterminator, and I'm now the proud owner of around 15 traps. (2 outdoor stations near the parking area, and the rest spread around the outbuildings I have around the property) Not really a point to this post, just commiserating that my less than 3 month old car already had mice in it. Hopefully the traps kill all the mice before they chew something in the car. (they destroyed my radio in the previous Gen 3)
Rustproofing like Krown or NHOU comprising of petroleum oils and waxes would serve the purpose of slowing down rust and repelling mice. Soy based wire insulation is an attractant to rodents. Petroleum based products repel them. My husband's and my friend recommended to me as he has used rustproofing for over 50 years and never had rodents chew anything in or around a car. My 7 year old Prius v has had no rodent activity. My husband even rustproofed his 2016 Nissan Versa Note. Rustproofing is cheap insurance, even if there is less rust here in the South. My husband worked on a 2016 Toyota 4runner. Rust has already started to corrode the chassis bolts we removed to do an oil change.
Used to have a rats nest on the truck battery and everyday evidence in the prius, plugged in some of theand no more rodents.
These have been found to be placebos that meets with the emotional needs of the buyer and owner, like the electrical based anode rustproofing sold to unsuspecting users. If "rustproofing" for rodent repellent is what you need, a one time treatment is all you need. Boeshield T9 available on Amazon for $114 a gallon is clear and nearly invisible. It can be applied in about and hour to the engine compartment area and for rustproofing, the seams of the underbody and contact points of plastic panels with painted metal and bolted areas. You wont need more than a quart. A cheap $5 Walmart gallon sprayer is a good applicator. The stuff is really thin. Flat painted surfaces are the last areas to start rusting and need not be coated.
I just discovered a mouse nest in my '07 Gen 2. I have been parking cars at this house for 11 years, 1.5 of which was said Prius with no rodent entry evidence. I feel your pain, but exterminator tactics are kind of useless (except for the exterminator, of course, he is making $$). There are MANY rodents and they multiply faster than exterminator can keep up (he knows this and that's his job security). What you want is to prevent or discourage entry to the vehicle cabin. This will also work when you park at a place that's not your house. Toyota should have addressed this three generations ago, but I guess it's still up to the owner. I have read numerous threads here on rodent entry (there is a LOT of information on this topic, so it's most definitely a thing) and found particular places on my model car to mouse proof. I used 1/4" galvanized mesh sold in most hardware stores ($10 for way more than you'll need to do one car). I have yet to complete the task as I have discovered information about more ingress points in addition to the ones I took care of. I wonder how rustproofing works on the Prius gen 2... One of the entryways is a drain channel in the front wheel wells (plastic), so I am not sure rustproofing can be applied there. Much simpler to cover openings with mesh, but the problem is knowing each and every one of the entry points. This is a perfect application of crowd sourcing and this forum is the perfect venue. Thank you all for the info. It really does help.
Put some 1/4" (grid size) galvanized steel mesh over the cabin air intake. You'll likely need to remove the wiper, wiper motor/linkage and bottom of windshield cowl for access.
They will keep coming. Best to use snap traps with peanut butter. Uses the ones with the plastic trigger plates that look like cheese. Metal ones don’t work as well. I had this problem in my highlanders. Their urine will keep attracting more mice to your car. I bought buckets of 3 various types of poisons a ton of traps and a jar of peanut butter. I have eliminated literally hundreds of them in the last few years. they now leave me alone.
If you're refering to the electronic rodent repelents, you couldn't be more incorrect. Rustproofing Toyota's is mandatory, they rust, but letting rodents at the engine compartment where they can eat anything and everything is a quick way to replacing the wiring on a toyota. Keeping them 25' away from the vehicle is simple, plug in a rodent repelant, I have a two car carport and a two car garage, they are 100' apart, each area has an electronic rodent repelant plugged in, they are more than five years old, zero sign of rodents since they were plugged in, they were three for five dollars, now they are three for twenty dollars.
Those sticky pads work well for me. Just put a drop of peanut butter in the center and bam...you have critters caught.
They usually come in when it starts to turn cold. By this time of year they should be done coming in. Can you rent a cat for the season?
I wish I could rent a cat. They came back and changed the bait on all the stations (15 of them). Including the two they sticky taped into the engine compartment. All of them had signs of being eaten. This was confirmed yesterday when a dying (not dead, it was having seizures) dropped from the kick panel and bounced off my leg onto the driver side floor mat. Never have I gone from 80MPH on the highway to dead stop in the breakdown lane that fast in my life. You guys are the only one's I can tell that it happened too. If I tell my wife, she'll never get in the car again. (I used the floor mat to flip it out onto the highway)
Sounds like the extermination route is not working out that well (at least it's not cheap). Try denial of entry approach. It's more sound. There are known entry points for rodents in the Prius. They are well documented and easily blocked by some mesh. No sticky traps, no dead animal, smell, no dying bodies falling on your person during driving. Extermination is just not a good way to go here from purely logical perspective. I think (and hope) you are learning this now. I have blocked off most of the known access points (the ones that lead to the top of the cabin filter, not the ones that lead directly into the cabin) and so far have had zero intrusion signs. Stay safe on those highways!
I've screened the cabin air intake so far, haven't dealt with the exhaust flaps at the aft corners, (wistfully?) thinking they're not that easy for rodents. I've also screened the engine air intake: heard rodents like nest in there, say in the box below the engine air filter.
I ha I have also not done the aft points. Mostly because I have not found evidence of entry into the cabin, only on top of the cabin filter. However, I plan on blocking the aft points as soon as it's a bit warmer out. I also read about additional points of entry (gen 2, mind) to the ones under the windshield. They are in front wheel wells behind the plastic covers. I think those actually are more likely to be used as they are closer to the ground. Again, so far no evidence of new ingress, so I postpone till weather is more kind to my hands. I have a friend with a gen 3 who lives in the countryside and the house is basically in the middle of the woods (more or less). She had infestation so bad that the insurance company almost totaled the car. All the interior had to be replaced and some of the wiring too. They ended up fixing instead of totaling, but it was a close call. Sounds like gen 4 is still prone to the same problem. I really wish Toyota addressed this in the design. I am all for the eco-friendly materials, but the rodent issue is definitely a consequence that needs to be addressed. I guess first they need to acknowledge it...