Close up of a Firebrat

Question

I’ve been finding what I thought were silverfish in a storeroom next to our fireplace. I brought them to the University of New Hampshire extension service and was told they were firebrats. I’ve never heard of firebrats; they look like silverfish to me. Are they the same insect?

Answer

They are two different insects, although closely related. And there are some differences in their appearance and habits. They have different temperature requirements and tend to occupy different places in a structure.

First, silverfish and firebrats do look very much alike. They are the same size (about ½ inch long) and same shape. They differ in their coloration though. Silverfish are a solid silvery or gray metallic color, while firebrats are a brown and gray mottled color. They both feed on the same kinds of foods, mostly starches, other carbohydrates, and proteins. That means they eat people food like flour, cereals, dried beef, but they also feed on starchy paper and glues in things like book bindings, wallpaper, gummed labels, envelopes, even starched fabrics. They’re both active at night, hiding during the day.

Temperature Range is the Key to the Difference

The main difference between silverfish and firebrats are the spaces they occupy. Firebrats like it hot. They thrive at temperatures between 98° F. and 102° . Firebrats’ “feet” are so heat-resistant that they can walk on top of furnaces, hot water pipes, and boilers. Needless to say, firebrats are found in sites where temperatures are high such as around ovens, furnaces, baseboard heaters, hot water pipes, and in hot attics. Because of this limited temperature range, firebrats are less often pests in homes and are more often pests in bakeries and commercial kitchens where they have the high heat and plenty of food.

Silverfish, on the other hand, are comfortable in more regions of our homes. They prefer damp, humid sites with temperatures between 70°-80°F. Silverfish can be found infesting basements, wall voids, cupboards, book shelves, laundry rooms, under sinks and near pipes, and in areas with still damp wallpaper, plaster, or drywall.

I’m guessing that the heat from your fireplace also warms the storage room and that the storage room contains plenty of cardboard boxes and other starchy paper material for the firebrats to feed on.

Give Colonial a call. Our technician will inspect your home to see whether you have firebrats in other areas as well. We can then design a pest management program to rid your home of firebrats.