Winter Insects

February 2026 Edition by: John Moore MSc

In a couple of my earlier posts, we discussed what happens to insects in the winter. We spoke about things like diapause, hibernation, and migration as survival strategies. However, we did not talk about one group of arthropods that seemingly is not concerned with the winter cold and does invade our businesses and homes, sometimes in mind-boggling numbers as we approach spring. These creatures have been observed many times in snow and ice and have even been documented living in the Arctic. They are active outside my own home now!

I am speaking about springtails (sometimes referred to as “snow fleas”). Although they are technically not insects, they are in a class of their own (Collembola), with roughly 9,000 recognized species. These arthropods can show up in your business or home in very large numbers even when temperatures are still cold and there is snow on the ground. They have unique abilities that prevent them from freezing. Most of them feed on decaying organic matter such as dead leaves, algae, and molds. They are extremely moisture-dependent and can desiccate rapidly, which is what sometimes drives them indoors to your business or home. This can be disturbing when you see tens of thousands of them jumping around outside—or inside bathrooms, kitchens, or any place that has water.

The good news: They are harmless. They do not bite, sting, spread disease, or cause damage. Despite being able to survive a robust winter, they are surprisingly fragile and do not do well indoors because the environment is too dry. They rarely live long once they come indoors unless you have an indoor swamp in your crawlspace! This is important to understand because when large numbers of them are on the move and putting pressure on the exterior of your facility, no pesticide application will stop the flow of springtails—there are simply too many of them. Once inside, a pesticide application is not necessary, as these arthropods will die very quickly if they cannot access enough moisture. On the rare occasions when I have seen springtails thriving inside a facility, it was the result of very poor sanitation, poor maintenance of processing equipment, and poor management of wastewater. Even then, a pesticide application would not have resolved the issue. The best control method available? Dry out the area they are inhabiting. This will reduce their numbers rapidly.