Have you seen an insect in your house that kind-of looks like a fly, but not exactly?  It will be black in color, but the stunning and key feature is the abdomen; it comes off the top of the abdomen and looks similar to a triangular flag.

I know of many people who have asked me about this “weird house fly” and when I tell them they shouldn’t squish they look at me like I’m crazy.  These “weird house flies” are ensign wasps and they help to manage cockroach populations.

The female ensign wasps seek out cockroach egg cases, known as ootheca, where she will lay an egg in one of the cockroach eggs inside the egg case.  The wasp’s egg will hatch and the larva will eat the egg in which is was laid. Successive instars of the larva eat the other eggs within the egg case.  The wasp pupates within the cockroach egg case and the adult emerges out when ready.

These wasps are not known to sting humans.

So what should you do if you find one in your house?  Leave the wasp alone and look for cockroaches!