Hi Heggie1
The only thing I know about sonar deterrants is re. the rat ones. They don’t work well out of doors because the rats become accustomed to them. But I did try a house one under shelter during the day once and didn’t get it in soon enough before a hog turned up early. I saw the hog visibly flinch when it went past the sonar deterrant. So I wouldn’t want to use them when there are hogs around. I fear fox ones may be similar, but haven’t tried one.
You may find that some sellers/makers of these deterrants claim they don’t affect hogs, but in reality I’m not sure there’s any way that they could actually know they don’t.
