Along with contact kill aerosols like Raid, mothballs are one of the most common pest control products bought and used by the general public. Unfortunately, that also makes them one of the most misused and misunderstood pest control products. As with any other chemical product, it must be used correctly to have any effect on pests.
First, let’s cover what mothballs actually are. These small white spheres are composed of a pesticide. Mothballs used to be made from Naphthalene, but now days are primarily made out of a chemical called 1,4-Dichlorobenzene due to worries about flammability. Just as with any other pesticide, mothballs have an EPA approved label with directions for use that must be adhered to. This is so that the mothballs are not only safely handled, but also effective. It is because chemical labels usually are not read thoroughly, that myths and misuse occur.
Myth #1: They’re repellents.
The biggest misconception with mothballs is that they are not actually meant to be used as repellents. Although they may have an unpleasant chemical odor to us, that does not mean insects will avoid them. Instead, mothballs release volatile vapors that will kill pests when they are present in sufficient concentrations. This leads into the second misconception about mothballs.
Myth #2: They work anywhere, so just throw a bunch of them everywhere.
Many people will throw mothballs in a closet or put them in the back of a cabinet or storage shelf, thinking that the smell will keep any moths or other damaging pests out. Unfortunately, this is not the case, and an open or non-airtight space may not allow for the vapor concentration to build up enough to kill pests. They are only effective in small, sealed containers.
Myth #3: They keep away snakes (and other large pests).
Another mothball myth is that, additionally to repelling insects (which they do not) they can also repel larger animals such as snakes, squirrels, and other rodents. People will scatter mothballs around their home, property, or crawlspace hoping to keep unwanted pests out. Not only is this not effective, but it is also damaging to the environment. Mothballs are basically solid balls of chemicals, which can easily leech out into the soil and water upon exposure, contaminating them. Exposure to mothball vapors over time can also cause lung and kidney damage. Remember if you can smell the mothballs, you are breathing in a pesticide.
In conclusion, mothballs can be highly effective at protecting your clothes and valuables. Just like any other pesticide though, the label must be followed (remember: ‘the label is law’) in order to maximize both safety and effectiveness.