I decided to try this trap because the regular snap traps were not catching anything…yet I could regularly hear that something was residing in my attic. I have since confirmed that what I am dealing with are roof rats. I have no idea how well it works for other critters.I made a minor modification to the trap, right off the bat…because the bait box didn’t seem to make a whole lot of sense for using loose food (which would fall through the holes and out the bottom). I found a shallow bowl that fit within the bait compartment would contain the food, but in doing so...did not allow the rats to actually reach the bait. To address this issue, I cut a hole in the side of the bait box to allow access to the bait from within the trap.The design concept of the trap otherwise seems reasonably sound and the trap looks to be well made. Unfortunately, the rats in my attic are a lot smarter than anticipated. I initially tried some dry dog food. As per the instructions, I wired the trap door open and spread some food near the entrance for a week before actually setting the trap … but a week later, I couldn’t tell that anything had even touched the bait.I then decided to install an infrared camera which is tied into my home network and records when it detects motion. The “rat cam” has been crucial to understanding what was going on. First off… I was shocked by how many rats were up there and by how wary they were of the trap. They also were not very interested in the dog food. Without a camera, I am sure I would have just kept relocating the trap, before figuring out that they were indeed traveling along routs near the trap, but they just were not interested in the bait. I re-baited the trap with squirrel food (a mixture of sun flower seeds and other grains), mixed with dried blueberries, and bacon bits. This mixture definitely got their attention. After a week, the rats seemed to be regularly feeding from the trap, so I unwired the door… only to discover that they would sit at the entrance as if politely waiting for the diner to open. Within a couple of days, none of the rats had entered the trap…but more surprisingly they were beginning to ignore the trap altogether. At the risk of teaching them how to escape, I even tried wiring the door half way open…but still nothing.I ended up wiring the door open again…allowing them to free feed for another 3 weeks, before re-baiting and setting the trap again. So…after a month…I had counted up to 10 rats at the trap at a single time…yet had caught zero rats.But…by this point, the vermin were much more comfortable with the trap…and I caught 8 rats in the 1st 24 hrs. I again wired the door open for a couple of days, and then set it again, to catch 2 more.However, the video reveals that I am only catching the younger rats. I have seen some that are much larger, that remain wary of the trap especially when set…but…at least for now, I did manage to significantly reduce the number of rats.Edit: I am updating this review and adding another star. I failed to mention a second modification that I made to the trap, because initially didn't believe it made any difference...but in the end, it did...but in an unanticipated way. The second modification was made because the 1st time that it was set, several rats would sit at the entrance and as soon as they would start to push to door down to enter, the cross bar which counter weights the door would come up and hit their tail, at which point it appeared they would startle and run. To address this problem, I cut the cross bar in the center and using 2 sets of pliers, I carefully bent the 2 ends so they were pointed up (do not try to do this without a good hold to prevent the counter weight from simply twisting, or it will break loose from the door). This modification did not seem to make any difference however with the rats.After the 1st month of getting the rats used to the trap, I managed to catch a total of 10 before they seemed to stop entering, so I wired the door open once again.A couple of nights later, I heard a loud shuffling noise in the attic. When I checked the rat cam, I was shocked to see what appeared to be Ratzilla half way in the trap. Since the door was wired open, I had no choice other than to patiently watch as the huge tail slowly slipped into the trap and I could see the reflection of eyes, as it worked its way around the bait compartment to face the camera. I then ran into the attic and was able to block the door before it could escaped. To my surprise, "Ratzilla" turned out to be a opossum. A couple of days later, I caught a second opossum. Reviewing the recordings on the rat cam, confirmed that both of the opossums had no trouble figuring out how to get into the trap...but because of their size, I don't think that they would have been able to depress the door, had the counter weight bar not been modified. I am thoroughly confused as to how the opossums were able to gain entry into my attic (because I have not been able to identify their entry point from the ground level). However, the good thing seems to be that since the opossums showed up, there have been no further rat sightings on the rat cam and the modified Ratinator is 2 for 2 on the opossums.