A Suggestion for Bait Station Manufacturers
Bait stations are boxes designed to restrict access by non-target animals (i.e. pets) and people (i.e. children). Bait stations also protect the bait from the harmful effects of weather, thereby helping to keep the bait fresh and palatable for rodents to consume.

As valuable as bait stations are, they are not perfect. Mouse-sized bait stations are typically not sufficiently strong for use outdoors. So people wanting to control mice outdoors often are forced to use the more durable rat-sized bait stations. You may say, “So what?” The problem is that rat-sized bait stations have openings that are large enough to allow rats to enter and find the bait. But if you only need to control mice, then the hole is too large by a factor of almost 2. While mice can still enter the larger opening, so can other animals such as ground squirrels and other non-target animals. So you may end up killing animals you don’t need to kill, but that it would raise the risk that you could kill animals that would be illegal to kill. If that doesn’t convince you of the problem, what about the wasted money in bait?
You could cut some screen and screw it over the opening to narrow the size to an inch or inch and half opening. But why don’t bait station manufacturers create stations with grooves by the opening where you could slide a piece of place with a narrower opening? Voila. The bait station would be a dual purpose one. The result would allow more targeted use of toxicants resulting in less rodenticide getting into the environment. Sounds like a win win for everyone.
Stephen M. Vantassel specializes in vertebrate pest issues. He is available for consultations, training, and writing.