These are a great idea in principle. Found them difficult to open once bait (Kaput rat poison granules) was installed because of the limited handling. Key didn't work as well do to weather and digging activity by rodent. In addition, they need some method of staking into the ground. Both stations ultimately disappeared in successive days even with a large stone placed on top of. My guess is a fox frequenting my area may have carried them away seeking a dead rodent inside. Or maybe the big barn owl that perched nearby.