There are a lot of gophers in the neighborhood but I have been lucky to have not had an issue with them for many years. Unfortunately they finally found my avocado tree and were popping holes (I am sure eating the roots) all around it the tree was stressing and dropping the small fruit. With the price of avocados I could not let this keep happening so with some research I found these repellers.I have to admit I was a little leery but gave them a try, I am happy I did. After setting them in the ground I still had holes showing up but the packaging stated give them a couple weeks to work. It has been about a month and I am not getting any more holes around the tree. I may have over done it but I put two in the area about 6 feet apart - I wanted as much protection as I could get.When I first put them in I did not sink them down far enough and I could hear the buzzing noise from my second floor bedroom when the window was open. I followed the instructions and used a metal stake to open up the hard soil deep enough and slide them in. With a little backfill of dirt you have to be within a couple of feet to hear the noise. They are about an inch out of the ground so I can get to the on / off switch on the underside of the solar panel. I was thinking there would be a reason to turn them off but now I don't see any reason to. I would not want the gophers to come back!I will post an update if I think they are not performing will but so far I am really happy.Overall great resultsMoles trashed my front yard in just a few days, tunneling 20 feet or more in a day. I tried repeatedly to eliminate them with baits/poisons and used repellents (castor oil liquids and powders). Very limited effects. I added in six of these stakes ringing the front yard and putting the other two at entry points from the side yards. Place the stakes thoughtfully, to ensure good coverage and adequate sunshine. After about five days in place, the moles seemed to move on towards my neighbor’s yard (he was doing nothing to address his mole issue, which seems to be where my moles migrated from, so I don’t feel badly that they went home). Don’t expect immediate results, but view these stakes as a part of an overall solution (I also have used traps). Follow the instructions as to pre-digging the right depth holes, and don’t push hard on the solar panel on the top of the stake and risk damaging them. I used a pointed broom handle and a hammer to get the right width and depth holes for inserting the stakes. Don’t rush it; do it right the first time.I purchased this product because I saw a few mole holes close to buildings/gardens where I prefer they don't dig. The stakes were easy to install, but I think it helps that I live in sandy terrain. As soon as I pressed the "on" button, they starting making the noise they give off. And after having them for about a month or so, they are still working, even the ones I placed in partial shade. The partially shaded ones aren't at full sound, of course, but are still working. I kept them above ground because I was hoping that would help repel other rodents, so I can hear the sound, but they are far enough away that it doesn't bother me.I believe they are working to prevent the moles from digging where I placed them as no new/closer holes have appeared. Would they have dug in those places anyways? I'm not sure. But so far the stakes have been a good preventative measure. I'm not sure how to completely avoid having moles, but maybe a combination of these stakes and other methods would keep them away for good?I didn't know if these would work and they have been in the ground for 3-4 weeks. This gopher loves to destroy both lawns when he is active. Over 20 years I have caught exactly 2 with spring traps and peanut butter. I don't know how many there are and there tracks are only about a foot down. The tips of these device go right into the runs, you can feel pushing them in that there is give. They are very sturdy and flat so you don't trip on them or hit the lawnmower - you shove them all the way down. They are solar and come charged somehow. You push a button and you can hear the disturbing noise if they are next to your ear, but not in the ground. You cannot hammer them in or you break the solar panel. If you need to wet the ground if its hard or pound a stake into the ground and put the emitter in that. Wherever he has dug up dirt somewhere around there is his pathway - try to find that with a narrow probe like a steel rod or stick then shove one in there, the other three I put on our side of the fence. He stopped coming over. I have read also, that they don't like it when you water over there paths because the ground collapses. That seems to make him go away. We also have a Kitty who will attack anything, she is second generation sabertooth and if the guy comes up, he's gone, but that has only happened once or twice. Smoke bombs nada, poisons you have to be careful of animals you like, kids and if you have anything edible near it. These are practically free, sturdy and I am glad they are working. The lawn is recovering. Thanks.Bought these for constantly recurring gopher holes all over our backyard. We have a large yard and back up onto BLM land with lots of wild creatures. Nothing has worked to deter the gophers - until now. I cover up the holes and within 3 days every hole is back. I've tried everything except traps and that is useless since the open land behind has an endless supply of gophers. So decided to try these deterents. Put them in about 3 weeks ago and not a single new hole. I have now bought another box of them for my front yard and my fence line.I've been fighting a mole in my front yard for months. I tried mole repellent pellets and balls. I didn't want to kill it but after a while it got so frustrating I tried poison mole food. Nothing worked and the mole killed big sections of grass. A friend suggested these. I bought this 4 pack and they absolutely worked. They were a little work to install cause some of my yard is hard packed, but once I turned them on, the mole vacated the area. The stakes only have a certain range and 4 doesn't cover enough of my yard, but I've ordered more and hope to be mole free soon.For 2 weeks I thought these had done the job. However the moles then came back and are even digging their holes right next to the stakes. I guess they got used to the sound. So unfortunately this was a rather expensive waste of money. I’m sad as I really thought they had solved the problem.