This is the season of home invaders, when some kinds of wildlife are eyeing our homes as a cozy place to pass the winter.
Houseflies are among these.
Out-of-doors, the adult flies will die off but the species survives the winter as larvae (a.k.a. maggots) or pupae — the shell in which they transform from larva to fly in the spring. So they’re not really going anywhere for the winter.
A favored location for larvae and pupae to survive the cold is under a pile of manure, but they can make do with your house.
A house fly can live up to 60 annoying days, but the good news is that without food, they only live about three days. Even if you’re not handy with a rolled newspaper, the problem is easily solved by not leaving garbage lying around!
Unless what you really have are cluster flies. They present a different challenge.
I first encountered cluster flies in upstate New York. It was spring and they were literally coming out of the woodwork in the house I rented, piling up between the windows and the screens. In my memory, there were hundreds trapped in each window, although maybe it was only 40 or 50.
We have them in Michigan, too. Unlike houseflies, cluster flies overwinter as adults, often in attics or inside walls. On warm days, they might break hibernation and enter your living space.
The two species look very similar. I find them easier to distinguish by their behavior. Are you suddenly seeing more inside your house in the winter or emerging in high numbers in the spring? Those are cluster flies.
These days, you might see house flies, cluster flies, Asian lady beetles, and marmorated stink bugs arriving at your door. One thing all these pests have in common is that none of them are native to North America.
