For years we had cats, lots of cats. So, no mice, rats, chipmunks. Old age and coyotes took out the cats about five years ago. Then, I ended up with an OEG bantam rooster who hates cats. We tried a kitten and Poppy made it quite clear, not in his house! So, the rodent population had to be controlled with bait, traps. We live a little over a mile from county landfill, so vigilance about rats is a must. Up until this summer I would rarely see a chipmunk, but often saw a rat. Now, over last three months I have not seen any rats, not even 'field' rats. But, there must be two dozen chimpmunks on the place! Now I know Guinea pig will kill a rat. But, have chipmunks run all the rats off? That would be great as chimpmunks don't get in coop or bother eggs/birds. None of bait being taken either. I have it in building where only rat would access.