Mice, Cheese, and a Side of Skepticism
Last summer, I spent about a month at a paleontology dig in Wyoming. For a paleo dig, we had it pretty luxurious. I had my own room in a trailer, down the street from the museum and down the hill from our dig site. Out in the field, a family of field mice had made our quarry their home. Back at the house, we had concerns about their house mice cousins moving in. Naturally, all the mouse-y-ness brought up the question of how to best attract and trap mice.
I’d never really thought much about it before. I like mice; I think they’re cute, and if they happen to move in, I prefer live traps to glue traps or the guillotine type. But any of these traps have to be baited. The common knowledge is that a chunk of cheese would do the trick. But as I talked with my supervisor about it, something struck me the wrong way. Why would mice eat cheese? There’s nothing like cheese in the wild. It’s a very human invention. Mice naturally eat seeds and nuts and grasses, which are nothing like cheese. On top of this, all the mousetraps in the trailer were baited with peanut butter, and my supervisor, as we discussed it more, mentioned that he’d never actually tried using cheese; he’d always used peanut butter as well, and it seemed to work. So where’d the cheese idea come from? And would it actually work?
Following my skeptical train-of-thought, I employed Google to see if anyone had tried this experiment before. And, lo and behold, they had. Dr. David Holmes, of Manchester Metropolitan University, ran a study on mice, seeing what attracted them most. He did an interview for Scientific American discussing his findings. It turns out they focus on things like smell and texture, and prefer foods high in carbohydrates and sugars. Peanut butter is perfect, because it smells and tastes like their natural food sources, and is sugar rich. Cheese, however, is too rich a food for mice, and isn’t like anything found in the wild. The idea of mice eating cheese seems to have propagated from the popular cartoon Tom and Jerry.
So, as it turns out, my skepticism of the myth of mice and cheese was well founded. We continued to bait the mousetraps with peanut butter, and also hired a cat from one of the interns to keep our trailer mouse-free. It just goes to show that skepticism is valuable in just about any situation.