Rodent Electronic Repellent for Car Engines Battery Operated Ultra Sonic Under Hood Animal Prevention Mice Chaser Rat Repelling Device, Pack of 4

These SIREN-ITE Rodent Electronic Repellent for Car Engines Battery Operated Ultra Sonic Under Hood Animal Prevention Mice Chaser Rat Repelling Device, Pack of 4 are marketed as a product that will help eliminate rodents from your vehicle or around your home, are they effective at performing that task?The answer to that question is a solid: Maybe? But probably not really.The first aspect of this that I wanted to mention is that generally these kinds of products are snake oil, there's no scientific evidence of these kinds of products being effective at repelling rodents or other pests. These are a little bit different than others that I've seen, and since we live with our house backed up to a hill that's a nature preserve, we have an abundance of rodents, specifically roof rats.These take AAA batteries to power, and I will say that they are fairly efficient because since I've installed them several weeks ago, I haven't needed to replace any of the batteries. Now, these do have several different modes to help deter pests. One of these modes creates an audible, and very annoying sound that can be heard by anyone. Just to be absolutely clear, I did test these with that sound on for 48 hours, and by the end of it I'm sure my neighbors were planning to violently remove these products, and I wouldn't blame them, I certainly hated hearing the noise as well. Did that sound work to deter any rodents? No, not really. It may have annoyed them as much as it annoyed us, but they still pretty much carried on with their business unperturbed by the noise.The other method of keeping rodents away is by using various flashing lights, I don't want to say that this is particularly effective, but there was a non-zero percent change in the activity of the rodents around these while the lights were flashing away. However, they would just avoid the area these were installed and find different routes to get up to the roof, because, after all, they are some crafty little buggers.Overall, these generally didn't have much of an effect on the rodent activity in the general vicinity of the areas they were installed. I have security cameras installed around my home and was still able to see their activity levels carried on as usual, with them generally just finding different paths to get to where they were going to avoid these boxes. The one thing these are effective at is turning the entire neighborhood against you because of how grating and annoying the sound they make is. So, if you're interested in becoming your neighborhood's pariah then these are excellent for that. 3/5 stars, I still think these products are mostly snake oil, but I gave it as fair of a run as I possibly could.

This is a handy kit of 4 ultrasonic emitters for cars. The principle is that the ultrasonic sounds (which we cannot hear) will be highly annoying to rodents and other critters and keep them from taking up tenancy in your cars (and chewing your wires, interior, etc). I have looked for some field mice or other rodents to ask them if the sounds are really annoying but all I got from Fred the Squirrel was some nasty chattering at me when I tried to ask him, and he ran away up the tree.They take batteries so they are easy to mount and keep out of the way with no cords.