Science Questions

A particular brand of mouthwash, they say Listerine, is a mosquito repellent. Can you think of any basic chemistry, why that should be the case? Susie Maruca and Marcie Lawson

We put this question to James Logan:

There are some compounds in Listerine such as menthol which does have a repellent effect against quite a lot of insects, actually. Perhaps it does have some sort of effect. I’m not sure if they’re saying it’s repellent by using it in their mouth or whether it’s repellent by putting it on their arms. I’m not sure but it’s certainly a new one. I hadn’t heard of that before.

May 2008